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Material for Database Class.

Clone URLs: https://rocketgit.com/user/caubert/CSCI_3410 ssh://rocketgit@ssh.rocketgit.com/user/caubert/CSCI_3410 git://git.rocketgit.com/user/caubert/CSCI_3410

master

List of commits:

Subject	Hash	Author	Date (UTC)
First quizz, and fix bug with code displayed.	bc9b6bb097e30186805b02dc1cdc5de2d5feabe4	caubert	2021-01-22 19:21:54
Edited the preamble.	364e709107602e163ea9365f25ccf1f5a6bb1914	caubert	2021-01-11 16:00:07
Started to edit notes and add final exam from fall 2020.	bb747e27ce08ce17e91913e947614e3057580995	caubert	2021-01-06 22:26:07
Integrated the include-link feature of pandoc-include-code.	3a8f9ededdaa1f05d526742f5d447aaa017e1d1b	caubert	2021-01-04 22:52:18
Fixed citeproc.	0d90c7e60e4a4474fd7ded03bb6526ea63a57253	aubert@math.cnrs.fr	2020-12-27 21:33:48
(Finally) updated pandoc and pandoc-numbering.	127c1964a0732b49e14b46fdb0d3f8446e3892d0	aubert@math.cnrs.fr	2020-12-27 21:14:31
Fixed url in comments, avoid them being wrapped.	09a6a78479f24b5749605a4cb7136f8cfbf57d30	aubert@math.cnrs.fr	2020-12-18 18:55:50
Added comments on procedures from code	f3e9c2abac41d5de1c7473867c4f688051dec928	aubert@math.cnrs.fr	2020-12-01 15:46:53
Updated mysql connector	228d86db5498aae94a4d162272fa03a84ae9c532	aubert@math.cnrs.fr	2020-12-01 15:09:46
Updated java beautifier	30f4a79f2d911cd0b6a24c31f968f0d23620965f	aubert@math.cnrs.fr	2020-12-01 15:07:50
Worked on procedure example from java	998ea14119a5a3f88efc4b0a126177e85151e43d	aubert@math.cnrs.fr	2020-12-01 15:06:47
Brief example of calling a procedure from a program.	1054c9d5c83fb956bdd0b8d884d5ce2c8a9a640e	aubert@math.cnrs.fr	2020-11-30 19:00:45
Added solution to second exam	d8f62ded96991885a96d561db587988d453a28c8	aubert@math.cnrs.fr	2020-11-05 20:35:50
Quick fix on testing semicolons.	7f48d88d2ed69213d803a7736df3d50330cfecd1	aubert@math.cnrs.fr	2020-11-03 14:14:06
Added simple example to test if semicolon are important in SQL querries.	98097fb11558c08bad630fb3351f99ceb6777de7	aubert@math.cnrs.fr	2020-11-03 14:11:22
Updated spots to https.	a8daf1768395aa296bf0dd05783dd53c757d5d19	aubert@math.cnrs.fr	2020-10-05 16:18:44
Adding quiz #2	98e0ae5b8ce766524f60c91adb1040235e1bbf31	aubert@math.cnrs.fr	2020-10-02 19:00:15
Added exam 1	e2f62ae4bf26fcc4b86e8665060ccf3918e7abeb	aubert@math.cnrs.fr	2020-09-24 12:51:36
worked on solution to first exam.	b13ad99dd895f124df1b642fd990071fc09db294	aubert@math.cnrs.fr	2020-09-23 17:44:01
Added solution to first problem.	0948cee47ed78dc115fd69c7bcf96a312dd3162f	aubert@math.cnrs.fr	2020-09-18 21:43:00

Commit bc9b6bb097e30186805b02dc1cdc5de2d5feabe4 - First quizz, and fix bug with code displayed.
Author: caubert
Author date (UTC): 2021-01-22 19:21
Committer name: caubert
Committer date (UTC): 2021-01-22 19:21
Parent(s): 364e709107602e163ea9365f25ccf1f5a6bb1914
Signer:
Signing key:
Signing status: N
Tree: e004b8f71521bd4a25ad0ee92bb8eecae61720c1

File	Lines added	Lines deleted
install/INSTALL.md	3	1
notes/lectures_notes.md	553	474

File install/INSTALL.md changed (mode: 100644) (index 18ea7f0..b960656)
...	...	Type: `git clone https://github.com/poonamveeral/GeneralRepo`
208	208
209	209	17) Test pandoc-include-code	17) Test pandoc-include-code
210	210	* In the same install folder, type:	* In the same install folder, type:
211		` `
	211
	212		`pandoc -F pandoc-include-code test_pandoc-include-code.md -o test_pandoc-include-code.html`
	213
212	214	* In the install folder, you should see a file called "test_pandoc-include-code.html" containing	* In the install folder, you should see a file called "test_pandoc-include-code.html" containing
213	215
214	216	```{html}	```{html}

File notes/lectures_notes.md changed (mode: 100644) (index 327de2e..fed0c2c)
...	...	Those are part of the definition of the relational model and are independent of
848	848	Those constraints are parts of the schema.	Those constraints are parts of the schema.
849	849
850	850	- The value must match its domain ("Domain constraint"), knowing that a domain can have additional constraints (`NOT NULL`, `UNIQUE`).	- The value must match its domain ("Domain constraint"), knowing that a domain can have additional constraints (`NOT NULL`, `UNIQUE`).
851		- The entity integrity constraint: no primary key value can be `NULL`.
	851		- The entity integrity constraint: no primary key value can be `NULL`^[This is also the way this is implemented in MySQL: no part of the primary key can have for value `NULL`. Cf. the ["Declaring Constraints"](#declaring-constraints-1) Section.].
852	852	- The referential integrity constraint: referred values must exist.	- The referential integrity constraint: referred values must exist.
853	853
854	854	Those last two constraints will be studied in the next section.	Those last two constraints will be studied in the next section.

...	...	and the following sets of attributes:
885	885	\| \| \{A, B, C, D\} \| \{A\} \| \{B, C\} \| \{D\} \|	\| \| \{A, B, C, D\} \| \{A\} \| \{B, C\} \| \{D\} \|
886	886	\| ---: \| :---: \| :---: \| :---: \| :---: \|	\| ---: \| :---: \| :---: \| :---: \| :---: \|
887	887	\| Superkey ? \| ✔ \| ✘ \| ✔ \| ✔ \|	\| Superkey ? \| ✔ \| ✘ \| ✔ \| ✔ \|
888		\| Key ?\| ✘ \| ✘ \| ✔ \| ✔ \|
	888		\| Key ?\| ✘ \| ✘ \| ✘ \| ✔ \|
889	889
890	890	Note that here we "retro-fit" those definitions, in database design, they come first (i.e., you define what attributes should always distinguish between tuples before populating your database).	Note that here we "retro-fit" those definitions, in database design, they come first (i.e., you define what attributes should always distinguish between tuples before populating your database).
891	891	We are making the assumption that the data pre-exist to the specification to make the concept clearer.	We are making the assumption that the data pre-exist to the specification to make the concept clearer.

...	...	If both elements were common, that would mean that we are registering a driver t
929	929
930	930	The operations you can perform on your data are of two kinds: retrievals and updates.	The operations you can perform on your data are of two kinds: retrievals and updates.
931	931
932		- Retrievals leave the relation state as it is and output a result relation. That is, retrieval: relation state → result relation
933		- Updates change the relation state. That is, update: relation state → relation state
	932		- Retrievals leave the relation(s) state as it is and output a result relation. That is, retrieval: relation(s) state → result relation
	933		- Updates change the relation(s) state. That is, update: relation(s) state → relation(s) state
934	934
935	935	They are two constraints for updates:	They are two constraints for updates:
936	936
937		#. The new relation state must be "valid" (i.e., comply with the state constraints).
	937		#. The new relation state must be "valid" (i.e., comply with the constraints).
938	938	#. There might be transition constraints (your balance cannot become negative, for instance).	#. There might be transition constraints (your balance cannot become negative, for instance).
939	939
940	940	A transaction is a series of retrievals and updates performed by an application program, that leaves the database in a consistent state.	A transaction is a series of retrievals and updates performed by an application program, that leaves the database in a consistent state.

...	...	Go back to the CAR example and populate it with some data to "see" how those opt
989	989
990	990	## Exercises {-}	## Exercises {-}
991	991
	992
992	993	Exercise .+#	Exercise .+#
993	994
994	995	: What are the meta-data and the data called in the relational model?	: What are the meta-data and the data called in the relational model?

...	...	Exercise +.#
1068	1069
1069	1070	: Define what is the domain constraint.	: Define what is the domain constraint.
1070	1071
	1072		Exercise +.#
	1073
	1074		: Circle the _correct_ statements:
	1075
	1076		- Every key is a superkey.
	1077		- Every superkey is a singleton.
	1078		- Every singleton is either a superkey, or a key.
	1079		- Every primary key is a key.
	1080		- Every superkey with one element is a key.
	1081
1071	1082	Exercise +.#	Exercise +.#
1072	1083	~	~
1073	1084

...	...	Solution +.#
1233	1244
1234	1245	: The requirement that each tuple must have for an attribute $A$ an atomic value from the domain dom($A$), or `NULL`.	: The requirement that each tuple must have for an attribute $A$ an atomic value from the domain dom($A$), or `NULL`.
1235	1246
	1247		Solution +.#
	1248
	1249		: "Every key is a superkey.", "Every primary key is a key." and "Every superkey with one element is a key." are correct statements.
	1250
1236	1251	Solution +.#	Solution +.#
1237	1252	~	~
1238	1253

...	...	TOY (Id (PK), Location, Description, Name, BestSuited (FK to TYPE.Name))
1487	1502
1488	1503	- [@Textbook6, ch. 4--5], [@Textbook7, ch. 6--7] describes `SQL`, but none of its implementation.	- [@Textbook6, ch. 4--5], [@Textbook7, ch. 6--7] describes `SQL`, but none of its implementation.
1489	1504	- To compare DBMS, you can look at their features, at <https://en.wikipedia.org/wiki/Comparison_of_relational_database_management_systems>, and at their popularity at <https://db-engines.com/en/ranking> and <https://insights.stackoverflow.com/survey/2020/#technology-databases> (if you sum up MySQL and MariaDB, they are first in both).	- To compare DBMS, you can look at their features, at <https://en.wikipedia.org/wiki/Comparison_of_relational_database_management_systems>, and at their popularity at <https://db-engines.com/en/ranking> and <https://insights.stackoverflow.com/survey/2020/#technology-databases> (if you sum up MySQL and MariaDB, they are first in both).
1490		- MySQL and MariaDB have some differences, you can look them up at < https://mariadb.com/kb/en/mariadb-vs-mysql-features/> and <https://mariadb.com/kb/en/mariadb-vs-mysql-compatibility/>.
	1505		- MySQL and MariaDB have some differences, you can look them up at <https://mariadb.com/kb/en/mariadb-vs-mysql-features/> and <https://mariadb.com/kb/en/mariadb-vs-mysql-compatibility/>.
1491	1506
1492	1507	This chapter will be "code-driven": the code will illustrate and help you understand some concepts.	This chapter will be "code-driven": the code will illustrate and help you understand some concepts.
1493	1508	You may want to have a look at the ["Setting Up Your Work Environment"](#sec:setup) Section as early as possible in this lecture.	You may want to have a look at the ["Setting Up Your Work Environment"](#sec:setup) Section as early as possible in this lecture.

...	...	The following is an adaptation of [w3resource.com](https://www.w3resource.com/my
1567	1582	- For monetary amounts, [it is recommended](https://stackoverflow.com/a/4397416) to use `DECIMAL(10, 2)` (or its synonym in MySQL `NUMERIC`).	- For monetary amounts, [it is recommended](https://stackoverflow.com/a/4397416) to use `DECIMAL(10, 2)` (or its synonym in MySQL `NUMERIC`).
1568	1583	- Characters can be stored using `CHAR` and `VARCHAR`: the length (resp. maximal length) of the `CHAR` (resp. `VARCHAR`) has to be declared, and `CHAR` are right-padded with spaces to the specified length.	- Characters can be stored using `CHAR` and `VARCHAR`: the length (resp. maximal length) of the `CHAR` (resp. `VARCHAR`) has to be declared, and `CHAR` are right-padded with spaces to the specified length.
1569	1584	Historically, [255](https://stackoverflow.com/q/1217466) was the size used, because it is the largest number of characters that can be counted with an 8-bit number, but, whenever possible, the "[right size](https://dba.stackexchange.com/a/183277)" should be used.	Historically, [255](https://stackoverflow.com/q/1217466) was the size used, because it is the largest number of characters that can be counted with an 8-bit number, but, whenever possible, the "[right size](https://dba.stackexchange.com/a/183277)" should be used.
1570		- You can store a single bit using `BIT(1)`, and a boolean using `BOOLEAN`.
1571		- For date and time types, you can use `DATE`, `TIME`, `DATETIME` and `TIMESTAMP`.
	1585		- You can store a single bit using `BIT(1)`, and a boolean using `BOOLEAN` (or `BOOL`, both actually being aliases for `TINYINT(1)`).
	1586		- For date and time types, you can use `DATE`, `TIME`, `DATETIME` and `TIMESTAMP` (which convert the current day / time to from the current time zone to UTC).
1572	1587
1573	1588	There are many other datatypes, but they really depends on the particular implementation, so we will not consider them too much.	There are many other datatypes, but they really depends on the particular implementation, so we will not consider them too much.
1574	1589

...	...	Note that
2450	2465	- The part `IS NOT NULL` is needed: otherwise, if one of the grade is `NULL`, then the comparison would yelds "unknown", and no grade would be greater than all of the others.	- The part `IS NOT NULL` is needed: otherwise, if one of the grade is `NULL`, then the comparison would yelds "unknown", and no grade would be greater than all of the others.
2451	2466	- This query could be simplified, using `MAX`:	- This query could be simplified, using `MAX`:
2452	2467
2453		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ProfExample.sql snippet=max}
2454		```
	2468		<!-- Bug, this code should be indented to be in the current environment. -->
	2469
	2470		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ProfExample.sql snippet=max}
	2471		```
2455	2472
2456	2473	Answering the question	Answering the question
2457	2474

...	...	Bye
2751	2768
2752	2769	We now log in as the normal user called "testuser".	We now log in as the normal user called "testuser".
2753	2770
2754		Linux users should type as a normal user, i.e., not as root, in their terminal the following, and Windows users should type in their command prompt the following^[Provided the working directory is still `C:\Program Files\MySQL\MySQL Server 8.0\bin` or similar. Cf. <https://dev.mysql.com/doc/mysql-windows-excerpt/8.0/en/mysql-installation-windows-path.html> to add the MySQL bin directory to your Windows system `PATH` environment variable.]:
	2771		Linux users should type as a normal user, i.e., not as root, in their terminal the following, and Windows users should type in their command prompt the following^[Provided the working directory is still `C:\Program Files\MySQL\MySQL Server 8.0\bin` or similar. Cf. <https://dev.mysql.com/doc/mysql-windows-excerpt/8.0/en/mysql-installation-windows-path.html> to add the MySQL bin directory to your Windows system `PATH` environment variable. For MacOS user, something like `sudo sh -c 'echo /usr/local/mysql/bin > /etc/paths.d/mysql'` should do.]:
2755	2772
2756	2773	```{.bash}	```{.bash}
2757	2774	mysql -u testuser -p	mysql -u testuser -p

...	...	Solution +.#
3205	3222	~	~
3206	3223	A simple and compact code could be:	A simple and compact code could be:
3207	3224
3208		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Short.sql snippet=solution}
3209		```
	3225		<!-- Bug, this code should be indented to be in the current environment. -->
	3226
	3227		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Short.sql snippet=solution}
	3228		```
3210	3229
3211	3230	Solution +.#	Solution +.#
3212	3231

...	...	Problem (Constraints on foreign keys) +.#fk
3580	3599
3581	3600	But, the situation is slightly more complex.	But, the situation is slightly more complex.
3582	3601	Test for yourself by editing the following code as indicated:	Test for yourself by editing the following code as indicated:
	3602
	3603		<!-- Bug, this code should be indented to be in the current environment. -->
3583	3604
3584		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_FKtest.sql}
3585		```
	3605		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_FKtest.sql}
	3606		```
3586	3607
3587		#. Remove the `PRIMARY KEY` constraint.
3588		#. Replace `PRIMARY KEY` with `UNIQUE`.
3589		#. Replace one of the `VARCHAR(25)` with `CHAR(25)`.
3590		#. Replace one of the `VARCHAR(25)` with `INT`.
3591		#. Replace one of the `VARCHAR(25)` with `VARCHAR(15)`
3592		#. Once you have edited and run the program in all of its modified versions, adjust the remarks above to better reflect the reality of the implementation we are using.
	3608		#. Remove the `PRIMARY KEY` constraint.
	3609		#. Replace `PRIMARY KEY` with `UNIQUE`.
	3610		#. Replace one of the `VARCHAR(25)` with `CHAR(25)`.
	3611		#. Replace one of the `VARCHAR(25)` with `INT`.
	3612		#. Replace one of the `VARCHAR(25)` with `VARCHAR(15)`
	3613		#. Once you have edited and run the program in all of its modified versions, adjust the remarks above to better reflect the reality of the implementation we are using.
3593	3614
3594	3615
3595	3616	---	---

...	...	Problem (Revisiting the PROF table) +.#profrevisited
3611	3632
3612	3633	The code we studied during the lecture is more or less the following.	The code we studied during the lecture is more or less the following.
3613	3634
3614		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ProfExampleRevisitedRevisited.sql snippet=recreate}
3615		```
3616
3617		We will resume working on this model, and enhance it.
	3635		<!-- Bug, this code should be indented to be in the current environment. -->
3618	3636
3619		@problem:profrevisited -- Question -.#
3620
3621		: Draw the complete relational model for this database (i.e., for the `PROF`, `DEPARTMENT`, `STUDENT` and `GRADE` relations).
	3637		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ProfExampleRevisitedRevisited.sql snippet=recreate}
	3638		```
3622	3639
3623		@problem:profrevisited -- Question -.#
3624		~
3625
3626		Create and populate a `LECTURE` table as follows:
	3640		We will resume working on this model, and enhance it.
3627	3641
3628		- It should have four attributes: `Name`, `Instructor`, `Code`, and `Year`, of types `VARCHAR(25)` for the first two, `CHAR(5)` for `Code`, and `YEAR(4)` for `Year`.
3629		- The `Year` and `Code` attributes should be the primary key (yes, have two attributes be the primary key).
3630		- The `Instructor` attribute should be a foreign key referencing the `Login` attribute in `PROF`.
3631		- Populate the `LECTURE` table with some made-up data.
	3642		@problem:profrevisited -- Question -.#
3632	3643
3633		Try to think about some of the weakenesses of this representation. For instance, can it accomodate two instructors for the same class? Write down two possibles scenarios in which this schema would not be appropriate.
	3644		: Draw the complete relational model for this database (i.e., for the `PROF`, `DEPARTMENT`, `STUDENT` and `GRADE` relations).
3634	3645
3635		@problem:profrevisited -- Question -.#
3636		~
3637		The `GRADE` table had some limitations too. For example, every student could have only one grade. Add two columns to the `GRADE` table using:
	3646		@problem:profrevisited -- Question -.#
	3647		~
3638	3648
3639		```
3640		ALTER TABLE GRADE
3641		ADD COLUMN LectureCode CHAR(5),
3642		ADD COLUMN LectureYear YEAR(4);
3643		```
3644
3645		Add a foreign key:
3646
3647		```
3648		ALTER TABLE GRADE
3649		ADD FOREIGN KEY (LectureYear, LectureCode)
3650		REFERENCES LECTURE(Year, Code);
3651		```
3652
3653		Use `DESCRIBE` and `SELECT` to observe the schema of the `GRADE` table and its rows. Is it what you would have expected?
	3649		Create and populate a `LECTURE` table as follows:
3654	3650
3655		@problem:profrevisited -- Question -.#
3656		: Update the tuples in `GRADE` with some made-up data. Now every row should contain, in addition to a login and a grade, a lecture year and a lecture code.
	3651		- It should have four attributes: `Name`, `Instructor`, `Code`, and `Year`, of types `VARCHAR(25)` for the first two, `CHAR(5)` for `Code`, and `YEAR(4)` for `Year`.
	3652		- The `Year` and `Code` attributes should be the primary key (yes, have two attributes be the primary key).
	3653		- The `Instructor` attribute should be a foreign key referencing the `Login` attribute in `PROF`.
	3654		- Populate the `LECTURE` table with some made-up data.
3657	3655
3658		@problem:profrevisited -- Question -.#
3659		: Update the relational model you previously drew to reflect the new situation of your tables.
	3656		Try to think about some of the weakenesses of this representation. For instance, can it accomodate two instructors for the same class? Write down two possibles scenarios in which this schema would not be appropriate.
3660	3657
3661		@problem:profrevisited -- Question -.#
3662		~
3663
3664		Write `SELECT` statements answering the following questions (where `PROF.Name`, `LECTURE.Name`, `YYYY`, `LECTURE.Code` and `STUDENT.Login` should be relevant values considering your data):
3665
3666		#. "Could you give me the logins and grades of the students who took `LECTURE.Name` in `YYYY`?"
3667		#. "Could you list the instructors who taught in year `YYYY` without any duplicates?"
3668		#. "Could you list the name and grade of all the student who ever took the class `LECTURE.Code`?"
3669		#. "Could you tell me which years was the class `LECTURE.Code` taught?"
3670		#. "Could you list the other classes taught the same year as the class `LECTURE.Code`?"
3671		#. "Could you print the names of the students who registered after `STUDENT.Login`?"
3672		#. "Could you tell me how many departments' heads are teaching this year?"
	3658		@problem:profrevisited -- Question -.#
	3659		~
	3660		The `GRADE` table had some limitations too. For example, every student could have only one grade. Add two columns to the `GRADE` table using:
	3661
	3662		```
	3663		ALTER TABLE GRADE
	3664		ADD COLUMN LectureCode CHAR(5),
	3665		ADD COLUMN LectureYear YEAR(4);
	3666		```
	3667
	3668		Add a foreign key:
	3669
	3670		```
	3671		ALTER TABLE GRADE
	3672		ADD FOREIGN KEY (LectureYear, LectureCode)
	3673		REFERENCES LECTURE(Year, Code);
	3674		```
	3675
	3676		Use `DESCRIBE` and `SELECT` to observe the schema of the `GRADE` table and its rows. Is it what you would have expected?
	3677
	3678		@problem:profrevisited -- Question -.#
	3679		: Update the tuples in `GRADE` with some made-up data. Now every row should contain, in addition to a login and a grade, a lecture year and a lecture code.
	3680
	3681		@problem:profrevisited -- Question -.#
	3682		: Update the relational model you previously drew to reflect the new situation of your tables.
	3683
	3684		@problem:profrevisited -- Question -.#
	3685		~
	3686
	3687		Write `SELECT` statements answering the following questions (where `PROF.Name`, `LECTURE.Name`, `YYYY`, `LECTURE.Code` and `STUDENT.Login` should be relevant values considering your data):
	3688
	3689		#. "Could you give me the logins and grades of the students who took `LECTURE.Name` in `YYYY`?"
	3690		#. "Could you list the instructors who taught in year `YYYY` without any duplicates?"
	3691		#. "Could you list the name and grade of all the student who ever took the class `LECTURE.Code`?"
	3692		#. "Could you tell me which years was the class `LECTURE.Code` taught?"
	3693		#. "Could you list the other classes taught the same year as the class `LECTURE.Code`?"
	3694		#. "Could you print the names of the students who registered after `STUDENT.Login`?"
	3695		#. "Could you tell me how many departments' heads are teaching this year?"
3673	3696
3674	3697	---	---
3675	3698

...	...	Problem (TRAIN table and more advanced `SQL` coding) +.#train
3678	3701
3679	3702	Look at the `SQL` code below and then answer the following questions.	Look at the `SQL` code below and then answer the following questions.
3680	3703
	3704		<!-- Bug, this code should be indented to be in the current environment. -->
	3705
3681	3706
3682		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Train.sql snippet=set-up}
3683		```
	3707		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Train.sql snippet=set-up}
	3708		```
3684	3709
3685		@problem:train -- Question -.#
	3710		@problem:train -- Question -.#
3686	3711
3687		: Modify the `CREATE` statement that creates the `TRAIN` table (lines 1--5), so that `ID` would be declared as the primary key. It is sufficient to only write the line(s) that need to change.
	3712		: Modify the `CREATE` statement that creates the `TRAIN` table (lines 1--5), so that `ID` would be declared as the primary key. It is sufficient to only write the line(s) that need to change.
3688	3713
3689		@problem:train -- Question -.#
	3714		@problem:train -- Question -.#
3690	3715
3691		: Write an `ALTER` statement that makes `ID` become the primary key of the `CONDUCTOR` table.
	3716		: Write an `ALTER` statement that makes `ID` become the primary key of the `CONDUCTOR` table.
3692	3717
3693		@problem:train -- Question -.#
	3718		@problem:train -- Question -.#
3694	3719
3695		: Modify the `CREATE` statement that creates the `ASSIGNED_TO` table (lines 13--18), so that it has two foreign keys: `ConductorId` references the `ID` attribute in `CONDUCTOR` and `TrainId` references the `ID` attribute in `TRAIN`. It is sufficient to only write the line(s) that need to change.
	3720		: Modify the `CREATE` statement that creates the `ASSIGNED_TO` table (lines 13--18), so that it has two foreign keys: `ConductorId` references the `ID` attribute in `CONDUCTOR` and `TrainId` references the `ID` attribute in `TRAIN`. It is sufficient to only write the line(s) that need to change.
3696	3721
3697		@problem:train -- Question -.#
	3722		@problem:train -- Question -.#
3698	3723
3699		: Write `INSERT` statements that insert one tuple of your choosing in each relation (no `NULL` values).
3700		These statements should respect all the constraints (including the ones we added in the previous questions) and result in actual insertions. (Remember that four digits is a valid value for an attribute with the `YEAR(4)` datatype.)
	3724		: Write `INSERT` statements that insert one tuple of your choosing in each relation (no `NULL` values).
	3725		These statements should respect all the constraints (including the ones we added in the previous questions) and result in actual insertions. (Remember that four digits is a valid value for an attribute with the `YEAR(4)` datatype.)
3701	3726
3702		@problem:train -- Question -.#
	3727		@problem:train -- Question -.#
	3728
	3729		: Write a statement that sets the value of the `ExperienceLevel` attribute to "Senior" in all the tuples where the `ID` attribute is "GP1029" in the `CONDUCTOR` relation.
	3730
	3731		@problem:train -- Question -.#
	3732		~
	3733		Write a `SELECT` statement that answers each of the following questions:
3703	3734
3704		: Write a statement that sets the value of the `ExperienceLevel` attribute to "Senior" in all the tuples where the `ID` attribute is "GP1029" in the `CONDUCTOR` relation.
	3735		#. "What are the identification numbers of the trains?"
	3736		#. "What are the names of the conductors with a "Senior" experience level?"
	3737		#. "What are the construction years of the "Surfliner" and "Regina" models that we have?"
	3738		#. "What is the ID of the conductor that was responsible of the train referenced "K-13" on 2015/12/14?"
	3739		#. "What are the models that were ever conducted by the conductor whose ID is "GP1029"?"
3705	3740
3706		@problem:train -- Question -.#
3707		~
3708		Write a `SELECT` statement that answers each of the following questions:
3709
3710		#. "What are the identification numbers of the trains?"
3711		#. "What are the names of the conductors with a "Senior" experience level?"
3712		#. "What are the construction years of the "Surfliner" and "Regina" models that we have?"
3713		#. "What is the ID of the conductor that was responsible of the train referenced "K-13" on 2015/12/14?"
3714		#. "What are the models that were ever conducted by the conductor whose ID is "GP1029"?"
3715
3716	3741	---	---
3717	3742
3718	3743	Problem (Read, correct, and write `SQL` statements for the COFFEE database) +.#coffee	Problem (Read, correct, and write `SQL` statements for the COFFEE database) +.#coffee

...	...	Problem (Write select queries for the DEPARTMENT table) +.#DepartmentSelect
3843	3868	~	~
3844	3869
3845	3870	Consider the following `SQL` code:	Consider the following `SQL` code:
3846
3847		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Department.sql snippet=statement}
3848		```
3849
3850		Write queries that return the following information. The values returned in this set-up will be in parenthesis, but keep the queries general.
3851	3871
3852		#. The name of the employees working in the `Storage` department (`"Bob"`, `"Samantha"`, `"Karen"` and `"Jocelyn"`),
3853		#. The name of the employee that has been hired for the longest period of time (`"Mark"`),
3854		#. The name(s) of the employee(s) from the `Storage` department who has(have) been hired for the longest period of time. Phrased differently, the oldest employees of the `Storage` department (`"Bob"` and `"Jocelyn"`).
	3872		<!-- Bug, this code should be indented to be in the current environment. -->
	3873
	3874		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Department.sql snippet=statement}
	3875		```
	3876
	3877		Write queries that return the following information. The values returned in this set-up will be in parenthesis, but keep the queries general.
	3878
	3879		#. The name of the employees working in the `Storage` department (`"Bob"`, `"Samantha"`, `"Karen"` and `"Jocelyn"`),
	3880		#. The name of the employee that has been hired for the longest period of time (`"Mark"`),
	3881		#. The name(s) of the employee(s) from the `Storage` department who has(have) been hired for the longest period of time. Phrased differently, the oldest employees of the `Storage` department (`"Bob"` and `"Jocelyn"`).
3855	3882
3856	3883	---	---
3857	3884

...	...	Problem (Write select queries for the COMPUTER table) +.#ComputerSelect
3861	3888
3862	3889	Consider the following `SQL` code:	Consider the following `SQL` code:
3863	3890
3864		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Computer.sql}
3865		```
3866
3867		Write queries that return the following information. The values returned in this set-up will be in parenthesis, but keep the queries general.
	3891		<!-- Bug, this code should be indented to be in the current environment. -->
	3892
	3893		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Computer.sql}
	3894		```
3868	3895
3869		#. The number of computers connected to the printer whose `ID` is `'13'` (`2`).
3870		#. The number of different models of printers (`2`).
3871		#. The model(s) of the printer(s) connected to the computer whose `ID` is `'A'` (`'HP-140'` and `'HP-139'`).
3872		#. The ID('s) of the computer(s) not connected to any printer (`'D'`).
	3896		Write queries that return the following information. The values returned in this set-up will be in parenthesis, but keep the queries general.
	3897
	3898		#. The number of computers connected to the printer whose `ID` is `'13'` (`2`).
	3899		#. The number of different models of printers (`2`).
	3900		#. The model(s) of the printer(s) connected to the computer whose `ID` is `'A'` (`'HP-140'` and `'HP-139'`).
	3901		#. The ID('s) of the computer(s) not connected to any printer (`'D'`).
3873	3902
3874	3903	---	---
3875	3904

...	...	Problem (Write select queries for the SocialMedia schema) +.#SocialMedia
3877	3906	~	~
3878	3907
3879	3908	Consider the following `SQL` code:	Consider the following `SQL` code:
3880
3881		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_SocialMedia.sql snippet=set-up}
3882		```
	3909		<!-- Bug, this code should be indented to be in the current environment. -->
3883	3910
3884		Write queries that return the following information. The values returned in this set-up will be in parenthesis, but keep the queries general.
3885	3911
3886		#. The title of all the videos (`"My first video!"`, `"My second video!"`, `"My vacations"`).
3887		#. The release date of the video whose title is `"My first video!"` (`"2020-02-02"`).
3888		#. The ID of the account(s) where the "Name" attribute was not given (`"2"`).
3889		#. The ID of the videos whose title contains the word `"video"` (`"10"`, `"20"`).
3890		#. The number of thumbs up for the video with title `"My vacations"` (`"1"`).
3891		#. The title of the oldest video (`"My first video!"`).
3892		#. The names of the accounts who gave a thumbs up to the video with ID 30 (`"Bob Ross"`).
3893		#. The ID of the account with the greatest number of subscribers (`"2"`).
	3912		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_SocialMedia.sql snippet=set-up}
	3913		```
	3914
	3915		Write queries that return the following information. The values returned in this set-up will be in parenthesis, but keep the queries general.
	3916
	3917		#. The title of all the videos (`"My first video!"`, `"My second video!"`, `"My vacations"`).
	3918		#. The release date of the video whose title is `"My first video!"` (`"2020-02-02"`).
	3919		#. The ID of the account(s) where the "Name" attribute was not given (`"2"`).
	3920		#. The ID of the videos whose title contains the word `"video"` (`"10"`, `"20"`).
	3921		#. The number of thumbs up for the video with title `"My vacations"` (`"1"`).
	3922		#. The title of the oldest video (`"My first video!"`).
	3923		#. The names of the accounts who gave a thumbs up to the video with ID 30 (`"Bob Ross"`).
	3924		#. The ID of the account with the greatest number of subscribers (`"2"`).
3894	3925
3895	3926
3896	3927	---	---

...	...	Problem (Write select queries for a variation of the COMPUTER table) +.#Computer
3901	3932
3902	3933	Consider the following `SQL` code:	Consider the following `SQL` code:
3903	3934
3904		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ComputerVariation.sql snippet=set-up}
3905		```
3906
3907		Write queries that return the following information. The values returned in this set-up will be in parenthesis, but keep the queries general.
	3935		<!-- Bug, this code should be indented to be in the current environment. -->
	3936
	3937		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ComputerVariation.sql snippet=set-up}
	3938		```
3908	3939
3909		#. The model of the computer whose `ID` is `'A'` (`'Apple IIc Plus'`).
3910		#. The type of the peripheral whose `ID` is `'14'` (`printer`).
3911		#. The model of the printers (Trendcom Model, TP-10 Thermal Matrix).
3912		#. The model of the peripherals whose `NAME` starts with `'IBM'` (`'IBM Selectric'`).
3913		#. The model of the peripherals connected to the computer whose `ID` is `'A'` (`Trendcom Model, IBM Selectric`).
3914		#. The number of peripheral connected to the computer whose model is Apple IIc Plus (`2`).
	3940		Write queries that return the following information. The values returned in this set-up will be in parenthesis, but keep the queries general.
	3941
	3942		#. The model of the computer whose `ID` is `'A'` (`'Apple IIc Plus'`).
	3943		#. The type of the peripheral whose `ID` is `'14'` (`printer`).
	3944		#. The model of the printers (Trendcom Model, TP-10 Thermal Matrix).
	3945		#. The model of the peripherals whose `NAME` starts with `'IBM'` (`'IBM Selectric'`).
	3946		#. The model of the peripherals connected to the computer whose `ID` is `'A'` (`Trendcom Model, IBM Selectric`).
	3947		#. The number of peripheral connected to the computer whose model is Apple IIc Plus (`2`).
3915	3948
3916	3949	---	---
3917	3950

...	...	Problem (A simple database for books) +.#sqlBooks
3964	3997
3965	3998	Consider the following code:	Consider the following code:
3966	3999
3967		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_SimpleBook.sql}
3968		```
	4000		<!-- Bug, this code should be indented to be in the current environment. -->
3969	4001
3970		The values inserted in the database is just to provide some examples; you should assume there is more data in it than what we have inserted.
3971		In this long problem, you will be asked to write commands to select, update, delete, insert data, and to improve upon the relational model.
3972	4002
3973		@problem:sqlBooks -- Question -.#
3974		~
3975
3976		Write a command that selects:
	4003		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_SimpleBook.sql}
	4004		```
3977	4005
3978		#. The `Title` of all the books.
3979		#. The distinct `Name` of the publishers.
3980		#. The `Titles` and `Published` dates of the books published since January 31, 2012.
3981		#. The first and last names of the authors published by `"Gallimard"` (from any city).
3982		#. The first and last names of the authors who were not published by an editor in `"New-York"`.
3983		#. The `ID` of the authors who published a book whose name starts with `"Where"`.
3984		#. The total number of pages in the database.
3985		#. The number of pages in the longest book written by the author whose last name is `"Wolve"`.
3986		#. The titles of the books published in the 19th century.
	4006		The values inserted in the database is just to provide some examples; you should assume there is more data in it than what we have inserted.
	4007		In this long problem, you will be asked to write commands to select, update, delete, insert data, and to improve upon the relational model.
3987	4008
3988		@problem:sqlBooks -- Question -.#
3989		: Write a command that updates the title of all the books written by the author whose `ID` is `3` to `"BANNED"`. Is there any reason for this command to be rejected by the system? If yes, explain the reason.
	4009		@problem:sqlBooks -- Question -.#
	4010		~
	4011
	4012		Write a command that selects:
	4013
	4014		#. The `Title` of all the books.
	4015		#. The distinct `Name` of the publishers.
	4016		#. The `Titles` and `Published` dates of the books published since January 31, 2012.
	4017		#. The first and last names of the authors published by `"Gallimard"` (from any city).
	4018		#. The first and last names of the authors who were not published by an editor in `"New-York"`.
	4019		#. The `ID` of the authors who published a book whose name starts with `"Where"`.
	4020		#. The total number of pages in the database.
	4021		#. The number of pages in the longest book written by the author whose last name is `"Wolve"`.
	4022		#. The titles of the books published in the 19th century.
3990	4023
3991		@problem:sqlBooks -- Question -.#
3992		: Write one or multiple commands that would delete the author whose `ID` is `3` and all the books written by that author. Make sure you do not violate any foreign key constraints.
	4024		@problem:sqlBooks -- Question -.#
	4025		: Write a command that updates the title of all the books written by the author whose `ID` is `3` to `"BANNED"`. Is there any reason for this command to be rejected by the system? If yes, explain the reason.
3993	4026
3994		@problem:sqlBooks -- Question -.#
3995		: Write a command that would create a table used to record the awards granted to authors for particular books. Assume that each award has its own name, is awarded every year, and that it is awarded to an author for a particular book. Pick appropriate attributes, datatypes^[You can use the `DATE` datatype to store a year.], primary and foreign keys, and, as always, avoid redundancy.
	4027		@problem:sqlBooks -- Question -.#
	4028		: Write one or multiple commands that would delete the author whose `ID` is `3` and all the books written by that author. Make sure you do not violate any foreign key constraints.
3996	4029
3997		@problem:sqlBooks -- Question -.#
3998		: Draw the relational model of the database you created (including all the relations given in the code and the ones you added).
	4030		@problem:sqlBooks -- Question -.#
	4031		: Write a command that would create a table used to record the awards granted to authors for particular books. Assume that each award has its own name, is awarded every year, and that it is awarded to an author for a particular book. Pick appropriate attributes, datatypes^[You can use the `DATE` datatype to store a year.], primary and foreign keys, and, as always, avoid redundancy.
3999	4032
4000		@problem:sqlBooks -- Question -.#
4001		: Discuss two limitations of the model and how to improve it.
	4033		@problem:sqlBooks -- Question -.#
	4034		: Draw the relational model of the database you created (including all the relations given in the code and the ones you added).
	4035
	4036		@problem:sqlBooks -- Question -.#
	4037		: Discuss two limitations of the model and how to improve it.
4002	4038
4003	4039	---	---
4004	4040

...	...	Problem (A simple database for published pieces of work) +.#sqlWorks
4076	4112
4077	4113	Consider the following code:	Consider the following code:
4078	4114
4079		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Work.sql snippet=set-up}
4080		```
4081
4082		Assume the following:
4083
4084		#. Every statement respects `SQL`'s syntax (there's no "a semi-colon is missing" trap).
4085		#. None of the commands in the rest of this problem are actually executed; they are for hypothetical "what if" questions.
4086
4087		Also, note that each row inserted between line 39 and 50 is given a name in comment (`"A.1, A.2, A.3, W.1"`, etc.).
	4115		<!-- Bug, this code should be indented to be in the current environment. -->
4088	4116
4089		@problem:sqlWorks -- Question -.#
4090		: Draw the relational model corresponding to this series of commands.
4091	4117
4092		@problem:sqlWorks -- Question -.#
4093		~
	4118		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Work.sql snippet=set-up}
	4119		```
	4120
	4121		Assume the following:
4094	4122
4095		Determine if the following insertion statements would violate the entity integrity constraint, the referential integrity constraint, if there would be some other kind of error, or if it would result in successful insertion.
	4123		#. Every statement respects `SQL`'s syntax (there's no "a semi-colon is missing" trap).
	4124		#. None of the commands in the rest of this problem are actually executed; they are for hypothetical "what if" questions.
4096	4125
4097		```
4098		INSERT INTO EBOOK VALUES (0, NULL, 20180101, 0);
4099		INSERT INTO AUTHOR VALUES("Mary B.", "mb@fai.fr", NULL);
4100		INSERT INTO WORK VALUES("My Life", "Claude A.");
4101		INSERT INTO BOOK VALUES(00000000, NULL, DATE'20001225', 90.9);
4102		INSERT INTO AUTHOR VALUES("Virginia W.", "alt@isp.net");
4103		```
	4126		Also, note that each row inserted between line 39 and 50 is given a name in comment (`"A.1, A.2, A.3, W.1"`, etc.).
	4127
	4128		@problem:sqlWorks -- Question -.#
	4129		: Draw the relational model corresponding to this series of commands.
	4130
	4131		@problem:sqlWorks -- Question -.#
	4132		~
	4133
	4134		Determine if the following insertion statements would violate the entity integrity constraint, the referential integrity constraint, if there would be some other kind of error, or if it would result in successful insertion.
	4135
	4136		```
	4137		INSERT INTO EBOOK VALUES (0, NULL, 20180101, 0);
	4138		INSERT INTO AUTHOR VALUES("Mary B.", "mb@fai.fr", NULL);
	4139		INSERT INTO WORK VALUES("My Life", "Claude A.");
	4140		INSERT INTO BOOK VALUES(00000000, NULL, DATE'20001225', 90.9);
	4141		INSERT INTO AUTHOR VALUES("Virginia W.", "alt@isp.net");
	4142		```
	4143
	4144		@problem:sqlWorks -- Question -.#
	4145		~
	4146
	4147		List the rows (A.2, W.1, etc.) modified by the following statements. Be careful about the conditions on foreign keys!
4104	4148
4105		@problem:sqlWorks -- Question -.#
4106		~
	4149		```
	4150		UPDATE AUTHOR SET Email = 'Deprecated' WHERE Email LIKE '%isp.net';
	4151		UPDATE WORK SET Title = "How to eat" WHERE Title = "What to eat";
	4152		DELETE FROM WORK;
	4153		DELETE FROM AUTHOR WHERE Name = "Virginia W.";
	4154		```
4107	4155
4108		List the rows (A.2, W.1, etc.) modified by the following statements. Be careful about the conditions on foreign keys!
4109
4110		```
4111		UPDATE AUTHOR SET Email = 'Deprecated' WHERE Email LIKE '%isp.net';
4112		UPDATE WORK SET Title = "How to eat" WHERE Title = "What to eat";
4113		DELETE FROM WORK;
4114		DELETE FROM AUTHOR WHERE Name = "Virginia W.";
4115		```
4116
4117		@problem:sqlWorks -- Question -.#
4118		~
4119		Assume that there is more data than what we inserted. Write a command that selects:
4120
4121		- The prices of all the ebooks.
4122		- The distinct names of the authors who have authored a piece of work.
4123		- The names of the authors using fai.fr for their email domain.
4124		- The prices of the ebooks published after 2018.
4125		- The price of the most expensive book.
4126		- The number of the pieces of work written by the author whose name is "Virginia W.."
4127		- The email of the author who wrote the piece called "My Life."
4128		- The ISBN's of the books containing a work written by the author whose email is "vw@isp.net."
4129
4130		@problem:sqlWorks -- Question -.#
4131		~
4132		Write a command that updates the title of all the pieces of work written by the author whose name is "Virginia W." to "BANNED."
4133		Is there any reason for this command to be rejected by the system?
4134		If yes, explain the reason.
	4156		@problem:sqlWorks -- Question -.#
	4157		~
	4158		Assume that there is more data than what we inserted. Write a command that selects:
	4159
	4160		- The prices of all the ebooks.
	4161		- The distinct names of the authors who have authored a piece of work.
	4162		- The names of the authors using fai.fr for their email domain.
	4163		- The prices of the ebooks published after 2018.
	4164		- The price of the most expensive book.
	4165		- The number of the pieces of work written by the author whose name is "Virginia W.."
	4166		- The email of the author who wrote the piece called "My Life."
	4167		- The ISBN's of the books containing a work written by the author whose email is "vw@isp.net."
4135	4168
4136		@problem:sqlWorks -- Question -.#
4137		: Write one or multiple commands that would delete the work whose title is "My Life", as well as all of the book and ebook versions of it.
	4169		@problem:sqlWorks -- Question -.#
	4170		~
	4171		Write a command that updates the title of all the pieces of work written by the author whose name is "Virginia W." to "BANNED."
	4172		Is there any reason for this command to be rejected by the system?
	4173		If yes, explain the reason.
	4174
	4175		@problem:sqlWorks -- Question -.#
	4176		: Write one or multiple commands that would delete the work whose title is "My Life", as well as all of the book and ebook versions of it.
	4177
	4178		@problem:sqlWorks -- Question -.#
	4179		: Discuss two limitations of the model and how to improve it.
4138	4180
4139		@problem:sqlWorks -- Question -.#
4140		: Discuss two limitations of the model and how to improve it.
4141	4181
4142
4143	4182	---	---
4144	4183
4145	4184	Problem (A simple database for authors of textbooks) +.#project1	Problem (A simple database for authors of textbooks) +.#project1
4146	4185	~	~
4147	4186
4148	4187	Consider the following code:	Consider the following code:
4149
4150
4151		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_TextbookAuthored.sql}
4152		```
4153		The meaning of the `AUTHORED` table is that a tuple $<I, L, F>$ represents that the author whose last name is L and whose first name is F wrote the textbook whose ISBN is I.
4154
4155		Answer the following:
4156
4157		#. Write a command that updates the email address of 'Gaddis', 'Tony.'
4158		#. Write a command that inserts a textbook of your choice into the `TEXTBOOK` table. No value should be `NULL`.
4159		#. Write a command that makes 'Gaddis', 'Tony' the author of the textbook you just added to our database.
4160		#. Write a command that makes "0.01" the default value for the `Price` attribute of the `TEXTBOOK` relation.
4161		#. Write a command that inserts a textbook of your choice in the `TEXTBOOK` table and have the price set to the default value.
4162		#. Write a command that creates a table called `EDITOR` with three attributes: `Name`, `Address`, and `Website`. The `Name` attribute should be the primary key. Insert two tuples in the `EDITOR` table, making sure that one should has the `Name` attribute set to "Pearson."
4163		#. Write a command that creates a table called `PUBLISHED` with two attributes: `Editor` and `Textbook`. The `Editor` attribute should reference the `EDITOR` table and the `Textbook` attribute should reference the `TEXTBOOK` table.
4164		#. Write a command that makes "Pearson" the editor of the textbook whose ISBN is 9780133776744.
4165
4166		Answer the following short questions based on what is in our model so far:
4167
4168		#. Can an author have authored more than one textbook?
4169		#. Can a textbook have more than one author?
4170		#. Can a textbook without an `ISBN` be inserted in the `TEXTBOOK` relation?
4171		#. Can the price of a textbook be negative?
4172		#. Can two authors have the same first and last names?
4173		#. Can two textbooks have the same title?
4174		#. Can two editors have the same address?
	4188
	4189		<!-- Bug, this code should be indented to be in the current environment. -->
	4190
	4191
	4192		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_TextbookAuthored.sql}
	4193		```
	4194		The meaning of the `AUTHORED` table is that a tuple $<I, L, F>$ represents that the author whose last name is L and whose first name is F wrote the textbook whose ISBN is I.
	4195
	4196		Answer the following:
	4197
	4198		#. Write a command that updates the email address of 'Gaddis', 'Tony.'
	4199		#. Write a command that inserts a textbook of your choice into the `TEXTBOOK` table. No value should be `NULL`.
	4200		#. Write a command that makes 'Gaddis', 'Tony' the author of the textbook you just added to our database.
	4201		#. Write a command that makes "0.01" the default value for the `Price` attribute of the `TEXTBOOK` relation.
	4202		#. Write a command that inserts a textbook of your choice in the `TEXTBOOK` table and have the price set to the default value.
	4203		#. Write a command that creates a table called `EDITOR` with three attributes: `Name`, `Address`, and `Website`. The `Name` attribute should be the primary key. Insert two tuples in the `EDITOR` table, making sure that one should has the `Name` attribute set to "Pearson."
	4204		#. Write a command that creates a table called `PUBLISHED` with two attributes: `Editor` and `Textbook`. The `Editor` attribute should reference the `EDITOR` table and the `Textbook` attribute should reference the `TEXTBOOK` table.
	4205		#. Write a command that makes "Pearson" the editor of the textbook whose ISBN is 9780133776744.
	4206
	4207		Answer the following short questions based on what is in our model so far:
	4208
	4209		#. Can an author have authored more than one textbook?
	4210		#. Can a textbook have more than one author?
	4211		#. Can a textbook without an `ISBN` be inserted in the `TEXTBOOK` relation?
	4212		#. Can the price of a textbook be negative?
	4213		#. Can two authors have the same first and last names?
	4214		#. Can two textbooks have the same title?
	4215		#. Can two editors have the same address?
4175	4216
4176	4217	---	---
4177	4218

...	...	Problem (A simple database for capstone projects) +.#project1bis
4180	4221
4181	4222	Consider the following code:	Consider the following code:
4182	4223
4183
4184		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Capstone.sql}
4185		```
4186		The meaning of the USED_LANGUAGE table is that a tuple $< N, L, U>$ represents the fact that the project whose code name is $N$ and whose leader is $L$ uses the programming language $U$.
	4224		<!-- Bug, this code should be indented to be in the current environment. -->
4187	4225
4188		@problem:project1bis -- Question -.#
4189	4226
4190		: Answer the following short questions based on the model implemented above.
4191		You can simply answer "True" or "False", or justify your reasoning (e.g. with code).
4192	4227
4193		#. Can a project uses multiple programming languages?
4194		#. Can a student be the leader of multiple projects?
4195		#. Can multiple projects have the same code name?
4196		#. Could Claude simply enter NULL for the value of his project's code name, since he's undecided?
4197		#. Can a project be created without project leader?
4198		#. Can we know who is working on a project without being its leader?
	4228		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Capstone.sql}
	4229		```
	4230		The meaning of the USED_LANGUAGE table is that a tuple $< N, L, U>$ represents the fact that the project whose code name is $N$ and whose leader is $L$ uses the programming language $U$.
4199	4231
4200		@problem:project1bis -- Question -.#
4201
4202		~ Draw the relational model corresponding to this code.
	4232		@problem:project1bis -- Question -.#
4203	4233
4204		@problem:project1bis -- Question -.#
4205
4206		: Write the following commands.
4207
4208		#. Write a command that insert a new student in the STUDENT table.
4209		#. Write a command that updates the code name of the project ("Undecided", "9999999999999") to "VR in ER".
4210		#. Write a command that updates the graduation year of the student whose id is "0987654321098" to 2024, and the semester to "Fall".
4211		#. Write a command that changes the STUDENT table to make it impossible to enter NULL for the first name of a student, without changing the primary key.
4212		#. Write a command that changes the datatype of GraduationYear to SMALLINT.
4213		#. Write a command that adds an attribute "ReleaseDate" to the PROJECT table.
4214		#. If you managed to write the previous command correctly, write a command that sets the release date of the project ("Brick Break", "0123456789100") to the 26th of November 2022.
4215		#. Write a command that makes it impossible for a student to be the leader in more than one project
	4234		: Answer the following short questions based on the model implemented above.
	4235		You can simply answer "True" or "False", or justify your reasoning (e.g. with code).
	4236
	4237		#. Can a project uses multiple programming languages?
	4238		#. Can a student be the leader of multiple projects?
	4239		#. Can multiple projects have the same code name?
	4240		#. Could Claude simply enter NULL for the value of his project's code name, since he's undecided?
	4241		#. Can a project be created without project leader?
	4242		#. Can we know who is working on a project without being its leader?
	4243
	4244		@problem:project1bis -- Question -.#
	4245
	4246		~ Draw the relational model corresponding to this code.
	4247
	4248		@problem:project1bis -- Question -.#
	4249
	4250		: Write the following commands.
	4251
	4252		#. Write a command that insert a new student in the STUDENT table.
	4253		#. Write a command that updates the code name of the project ("Undecided", "9999999999999") to "VR in ER".
	4254		#. Write a command that updates the graduation year of the student whose id is "0987654321098" to 2024, and the semester to "Fall".
	4255		#. Write a command that changes the STUDENT table to make it impossible to enter NULL for the first name of a student, without changing the primary key.
	4256		#. Write a command that changes the datatype of GraduationYear to SMALLINT.
	4257		#. Write a command that adds an attribute "ReleaseDate" to the PROJECT table.
	4258		#. If you managed to write the previous command correctly, write a command that sets the release date of the project ("Brick Break", "0123456789100") to the 26th of November 2022.
	4259		#. Write a command that makes it impossible for a student to be the leader in more than one project
4216	4260
4217	4261	---	---
4218	4262

...	...	Problem (A database for residencies) +.#residency
4221	4265
4222	4266	Consider the following code:	Consider the following code:
4223	4267
4224
4225		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Residency.sql}
4226		```
4227		Note that each row inserted in the `PERSON`, `HOUSE` and `RESIDENCY` tables is given the name and noted as afterwards as a comment (`"P.1, P.2, P.3, P.4, H.1"`, etc.).
	4268		<!-- Bug, this code should be indented to be in the current environment. -->
4228	4269
4229		Answer the following questions and problems, assuming that none of the commands in the rest of the problem are actually executed.
4230	4270
4231		@problem:residency -- Question -.#
4232	4271
4233		: Draw the relational model corresponding to this series of commands (it is not necessary to include the state).
4234
4235		@problem:residency -- Question -.#
4236		: Write a command that violates the entity integrity constraint.
	4272		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Residency.sql}
	4273		```
	4274		Note that each row inserted in the `PERSON`, `HOUSE` and `RESIDENCY` tables is given the name and noted as afterwards as a comment (`"P.1, P.2, P.3, P.4, H.1"`, etc.).
4237	4275
4238		@problem:residency -- Question -.#
4239		: Write a command that violates the referential integrity constraint.
	4276		Answer the following questions and problems, assuming that none of the commands in the rest of the problem are actually executed.
4240	4277
4241		@problem:residency -- Question -.#
4242		: List the rows (e.g. "P.2", "H.1", or "none") modified by the following statements:
	4278		@problem:residency -- Question -.#
4243	4279
4244		#. `UPDATE HOUSE SET COLOR = "green";`
4245		#. `DELETE FROM RESIDENCY WHERE House LIKE "1%";`
4246		#. `DELETE FROM HOUSE WHERE Address = "456 Second St.";`
4247		#. `DELETE FROM PERSON WHERE Birthdate=DATE"1990-02-11";`
	4280		: Draw the relational model corresponding to this series of commands (it is not necessary to include the state).
4248	4281
4249		@problem:residency -- Question -.#
4250		~
4251
4252		Write queries that return the following information. The values returned in this set-up will be in parenthesis, but keep the queries general.
4253
4254		#. The `Addresses' of the houses in the system (`"11 Third St., 123 Main St., 456 Second St."`).
4255		#. The `SSN`'s of the people whose first name was not entered in the system (`"000-00-0000"`).
4256		#. All the different colors of houses (`"white, blue"`).
4257		#. The `Address` of the residency of `"James Baldwin"` (`"123 Main St."`).
4258		#. The first name of the oldest person in the database (`"James"`).
4259		#. `"Michael Keal"`'s principal residency address (`"123 Main St."`).
4260		#. The distinct first and last names of the homeowners (`"Michael Keal, Mridula Warrier"`).
4261		#. The `SSN`'s of the people that have the same principal residency as `"James Baldwin"` (`"000-00-0001"`).
4262
4263		@problem:residency -- Question -.#
4264		: Write a command that updates the `SSN` of `"James Baldwin"` to `"000-00-0010"`. Is there any reason for this command to be rejected by the system? If yes, explain the reason.
4265
4266		@problem:residency -- Question -.#
4267		~
4268		Answer the following short questions from the data in our model, as it is currently:
	4282		@problem:residency -- Question -.#
	4283		: Write a command that violates the entity integrity constraint.
	4284
	4285		@problem:residency -- Question -.#
	4286		: Write a command that violates the referential integrity constraint.
	4287
	4288		@problem:residency -- Question -.#
	4289		: List the rows (e.g. "P.2", "H.1", or "none") modified by the following statements:
	4290
	4291		#. `UPDATE HOUSE SET COLOR = "green";`
	4292		#. `DELETE FROM RESIDENCY WHERE House LIKE "1%";`
	4293		#. `DELETE FROM HOUSE WHERE Address = "456 Second St.";`
	4294		#. `DELETE FROM PERSON WHERE Birthdate=DATE"1990-02-11";`
	4295
	4296		@problem:residency -- Question -.#
	4297		~
4269	4298
4270		#. Is it possible for two people to have the same last name?
4271		#. Is it possible for a person to have multiple principal residencies?
4272		#. Is it possible for a house to not be yellow?
4273		#. Is it possible for the `SSN` to be any series of 11 characters?
4274		#. Is it possible for a person to own any number of houses?
4275		#. Is it possible for a person to rent at most one house?
	4299		Write queries that return the following information. The values returned in this set-up will be in parenthesis, but keep the queries general.
	4300
	4301		#. The `Addresses' of the houses in the system (`"11 Third St., 123 Main St., 456 Second St."`).
	4302		#. The `SSN`'s of the people whose first name was not entered in the system (`"000-00-0000"`).
	4303		#. All the different colors of houses (`"white, blue"`).
	4304		#. The `Address` of the residency of `"James Baldwin"` (`"123 Main St."`).
	4305		#. The first name of the oldest person in the database (`"James"`).
	4306		#. `"Michael Keal"`'s principal residency address (`"123 Main St."`).
	4307		#. The distinct first and last names of the homeowners (`"Michael Keal, Mridula Warrier"`).
	4308		#. The `SSN`'s of the people that have the same principal residency as `"James Baldwin"` (`"000-00-0001"`).
	4309
	4310		@problem:residency -- Question -.#
	4311		: Write a command that updates the `SSN` of `"James Baldwin"` to `"000-00-0010"`. Is there any reason for this command to be rejected by the system? If yes, explain the reason.
	4312
	4313		@problem:residency -- Question -.#
	4314		~
	4315		Answer the following short questions from the data in our model, as it is currently:
4276	4316
4277		@problem:residency -- Question -.#
4278		: Consider the data currently in the `RESIDENCY` table and give a possible primary key.
	4317		#. Is it possible for two people to have the same last name?
	4318		#. Is it possible for a person to have multiple principal residencies?
	4319		#. Is it possible for a house to not be yellow?
	4320		#. Is it possible for the `SSN` to be any series of 11 characters?
	4321		#. Is it possible for a person to own any number of houses?
	4322		#. Is it possible for a person to rent at most one house?
4279	4323
4280		@problem:residency -- Question -.#
4281		: Discuss why the primary key identified from the previous question for the `RESIDENCY` table is a good choice.
	4324		@problem:residency -- Question -.#
	4325		: Consider the data currently in the `RESIDENCY` table and give a possible primary key.
	4326
	4327		@problem:residency -- Question -.#
	4328		: Discuss why the primary key identified from the previous question for the `RESIDENCY` table is a good choice.
4282	4329
4283	4330
4284	4331	---	---

...	...	Problem (A database for research fundings) +.#research-funding
4287	4334	~	~
4288	4335
4289	4336	Consider the following code:	Consider the following code:
4290
4291
4292		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ScientificResearch.sql snippet=statement}
4293		```
4294		Note that each row inserted in the tables is given a name and noted as afterwards as a comment (`"S.1, S.2, P.1, C.1, FA.1"`, etc.).
4295	4337
4296		Answer the following questions and problems, assuming that none of the commands in the rest of the problem are actually executed.
	4338		<!-- Bug, this code should be indented to be in the current environment. -->
4297	4339
4298		@problem:research-funding -- Question -.#
4299	4340
4300		: Draw the relational model corresponding to this series of commands (it is not necessary to include the state).
4301
4302		@problem:research-funding -- Question -.#
4303	4341
4304		: Draw the relational model corresponding to this series of commands (no need to include the state).
	4342		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ScientificResearch.sql snippet=statement}
	4343		```
	4344		Note that each row inserted in the tables is given a name and noted as afterwards as a comment (`"S.1, S.2, P.1, C.1, FA.1"`, etc.).
	4345
	4346		Answer the following questions and problems, assuming that none of the commands in the rest of the problem are actually executed.
	4347
	4348		@problem:research-funding -- Question -.#
	4349
	4350		: Draw the relational model corresponding to this series of commands (it is not necessary to include the state).
	4351
	4352		@problem:research-funding -- Question -.#
4305	4353
4306		@problem:research-funding -- Question -.#
	4354		: Draw the relational model corresponding to this series of commands (no need to include the state).
4307	4355
4308		: How could you edit line 12 so that negative values and `NULL`{.sql} would not be admitted as values for `Hours`{.sql}?
	4356		@problem:research-funding -- Question -.#
4309	4357
4310		@problem:research-funding -- Question -.#
	4358		: How could you edit line 12 so that negative values and `NULL`{.sql} would not be admitted as values for `Hours`{.sql}?
4311	4359
4312		: Write a command that would violate the referential integrity constraint.
	4360		@problem:research-funding -- Question -.#
4313	4361
4314		@problem:research-funding -- Question -.#
	4362		: Write a command that would violate the referential integrity constraint.
4315	4363
4316		: List the rows affected (updated or deleted) by the following commands. If no rows are affected because the command would would violate the entity integrity constraint, the referential integrity constraint, or if there would be some other kind of error, please indicate it.
	4364		@problem:research-funding -- Question -.#
4317	4365
4318		#. `UPDATE SCIENTIST SET SSN = "000000001" WHERE Name = "Claire";`{.sql}
4319		#. `UPDATE FUNDINGAGENCY SET Name = "NSF" WHERE Name = "National Science Foundation";`{.sql}
4320		#. `DELETE FROM FUNDINGAGENCY WHERE Name = "French-American Cultural Exchange";`{.sql}
	4366		: List the rows affected (updated or deleted) by the following commands. If no rows are affected because the command would would violate the entity integrity constraint, the referential integrity constraint, or if there would be some other kind of error, please indicate it.
4321	4367
4322		@problem:research-funding -- Question -.#
	4368		#. `UPDATE SCIENTIST SET SSN = "000000001" WHERE Name = "Claire";`{.sql}
	4369		#. `UPDATE FUNDINGAGENCY SET Name = "NSF" WHERE Name = "National Science Foundation";`{.sql}
	4370		#. `DELETE FROM FUNDINGAGENCY WHERE Name = "French-American Cultural Exchange";`{.sql}
4323	4371
4324		: Write a query that selects …(In parenthesis, the values returned in this set-up, but you have to be general.)
	4372		@problem:research-funding -- Question -.#
4325	4373
4326		#. …the name of the funding agencies created after 2000 (\"French-American Cultural Exchange\")
	4374		: Write a query that selects …(In parenthesis, the values returned in this set-up, but you have to be general.)
4327	4375
4328		#. …the code of the projects that contains the word \"Airplanes\" (\"AA\", \"BA\")
	4376		#. …the name of the funding agencies created after 2000 (\"French-American Cultural Exchange\")
4329	4377
4330		#. …the number of hours scientists contributed to the project \"AA\" (18)
	4378		#. …the code of the projects that contains the word \"Airplanes\" (\"AA\", \"BA\")
4331	4379
4332		#. …the code of the projects to which the scientist named Sabine contributed (\"AA\", \"BB\")
	4380		#. …the number of hours scientists contributed to the project \"AA\" (18)
4333	4381
4334		#. …the name of the projects who benefited from federal funds (\"Advancing Airplanes\")
	4382		#. …the code of the projects to which the scientist named Sabine contributed (\"AA\", \"BB\")
4335	4383
4336		#. …the name of the scientist who contributed to the same project as Mike (\"Sabine\", \"James\")
	4384		#. …the name of the projects who benefited from federal funds (\"Advancing Airplanes\")
4337	4385
4338		#. …the name of the projects that are not funded by an agency (\"Better Airplanes\", \"Better Buildings\")
	4386		#. …the name of the scientist who contributed to the same project as Mike (\"Sabine\", \"James\")
4339	4387
4340		#. …the name of the scientist who contributed the most (in terms of hours) to the project named \"Advancing Airplanes\" (Sabine).
	4388		#. …the name of the projects that are not funded by an agency (\"Better Airplanes\", \"Better Buildings\")
4341	4389
4342		@problem:research-funding -- Question -.#
	4390		#. …the name of the scientist who contributed the most (in terms of hours) to the project named \"Advancing Airplanes\" (Sabine).
4343	4391
4344		: Identify and discuss two limitations of this model, and offer a way to remedy at least one of them.
	4392		@problem:research-funding -- Question -.#
	4393
	4394		: Identify and discuss two limitations of this model, and offer a way to remedy at least one of them.
4345	4395
4346	4396
4347	4397	## Solutions to Selected Problems {-}	## Solutions to Selected Problems {-}

...	...	Solution to [%D %n (%T)](#problem:profrevisited)
4644	4694	~	~
4645	4695
4646	4696	The code is straightforward:	The code is straightforward:
4647
4648		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ProfExampleRevisitedRevisited.sql snippet=lecture}
4649		```
4650		However, this representation can not handle the following situations:
4651
4652		- If multiple instructors teach the same class,
4653		- If the lecture is taught more than once a year (either because it is taught in the Fall, Spring and Summer, or if multiple sections are offered at the same time),
4654		- If a Lecture is cross-listed, then some duplication of information will be needed.
4655
4656		We come back to those short-coming in the ["Reverse-Engineering"](#reverse-engineering-1) section, using more abstract tools (such as Entity Diagrams) that have not been introduced yet.
4657
4658		@problem:profrevisited-- Solution to Q. -.#
4659		~
	4697
	4698		<!-- Bug, this code should be indented to be in the current environment. -->
4660	4699
4661		The statements are immediate:
4662
4663		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ProfExampleRevisitedRevisited.sql snippet=grade}
4664		```
4665
4666		What may be surprising is that the values for `LectureCode` and `LectureYear` are set to `NULL` in all the tuples.
4667	4700
4668		@problem:profrevisited-- Solution to Q. -.#
4669		~
	4701		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ProfExampleRevisitedRevisited.sql snippet=lecture}
	4702		```
	4703		However, this representation can not handle the following situations:
4670	4704
4671		We use `UPDATE` statements:
4672
4673		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ProfExampleRevisitedRevisited.sql snippet=update}
4674		```
4675
4676		@problem:profrevisited-- Solution to Q. -.#
4677		~
4678		We refer back to the solution to Q. 1.
4679
4680		@problem:profrevisited-- Solution to Q. -.#
4681		~
	4705		- If multiple instructors teach the same class,
	4706		- If the lecture is taught more than once a year (either because it is taught in the Fall, Spring and Summer, or if multiple sections are offered at the same time),
	4707		- If a Lecture is cross-listed, then some duplication of information will be needed.
4682	4708
4683		We use `SELECT` statements:
4684
4685		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ProfExampleRevisitedRevisited.sql snippet=select}
4686		```
	4709		We come back to those short-coming in the ["Reverse-Engineering"](#reverse-engineering-1) section, using more abstract tools (such as Entity Diagrams) that have not been introduced yet.
	4710
	4711		@problem:profrevisited-- Solution to Q. -.#
	4712		~
	4713
	4714		The statements are immediate:
	4715
	4716		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ProfExampleRevisitedRevisited.sql snippet=grade}
	4717		```
	4718
	4719		What may be surprising is that the values for `LectureCode` and `LectureYear` are set to `NULL` in all the tuples.
	4720
	4721		@problem:profrevisited-- Solution to Q. -.#
	4722		~
	4723
	4724		We use `UPDATE` statements:
	4725
	4726		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ProfExampleRevisitedRevisited.sql snippet=update}
	4727		```
	4728
	4729		@problem:profrevisited-- Solution to Q. -.#
	4730		~
	4731		We refer back to the solution to Q. 1.
	4732
	4733		@problem:profrevisited-- Solution to Q. -.#
	4734		~
	4735
	4736		We use `SELECT` statements:
	4737
	4738		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ProfExampleRevisitedRevisited.sql snippet=select}
	4739		```
4687	4740	---	---
4688	4741
4689	4742	Solution to [%D %n (%T)](#problem:train)	Solution to [%D %n (%T)](#problem:train)

...	...	Solution to [%D %n (%T)](#problem:train)
4691	4744
4692	4745	The code below includes the answers to all of the questions for this problem:	The code below includes the answers to all of the questions for this problem:
4693	4746
4694		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Train.sql snippet=solution}
4695		```
	4747		<!-- Bug, this code should be indented to be in the current environment. -->
	4748
	4749		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Train.sql snippet=solution}
	4750		```
4696	4751
4697	4752	---	---
4698	4753

...	...	Solution to [%D %n (%T)](#problem:coffee)
4711	4766
4712	4767
4713	4768	The answers to the rest of the questions are in the following code:	The answers to the rest of the questions are in the following code:
4714
4715		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_DBCoffee.sql snippet=solution}
4716		```
	4769		<!-- Bug, this code should be indented to be in the current environment. -->
	4770
	4771
	4772		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_DBCoffee.sql snippet=solution}
	4773		```
4717	4774
4718	4775	---	---
4719	4776
4720	4777	Solution to [%D %n (%T)](#problem:DepartmentSelect)	Solution to [%D %n (%T)](#problem:DepartmentSelect)
4721	4778
4722	4779	~	~
	4780		<!-- Bug, this code should be indented to be in the current environment. -->
	4781		<!-- Plus, for this case, restore the list. -->
	4782
4723	4783
4724		#. ```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Department.sql snippet=solution1}
4725		```
4726
4727		#. ```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Department.sql snippet=solution2}
4728		```
4729
4730		#. ```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Department.sql snippet=solution3}
4731		```
	4784		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Department.sql snippet=solution1}
	4785		```
	4786
	4787		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Department.sql snippet=solution2}
	4788		```
	4789
	4790		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Department.sql snippet=solution3}
	4791		```
4732	4792	---	---
4733	4793
4734	4794	Solution to [%D %n (%T)](#problem:ComputerSelectBis)	Solution to [%D %n (%T)](#problem:ComputerSelectBis)
4735	4795
4736	4796	~	~
4737	4797
4738		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ComputerVariation.sql snippet=solution}
4739		```
	4798		<!-- Bug, this code should be indented to be in the current environment. -->
	4799
	4800		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ComputerVariation.sql snippet=solution}
	4801		```
4740	4802
4741	4803	---	---
4742	4804
4743	4805	Solution to [%D %n (%T)](#problem:SocialMedia)	Solution to [%D %n (%T)](#problem:SocialMedia)
4744	4806	~	~
4745	4807
4746		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_SocialMedia.sql snippet=solution}
4747		```
	4808		<!-- Bug, this code should be indented to be in the current environment. -->
	4809
	4810		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_SocialMedia.sql snippet=solution}
	4811		```
4748	4812
4749	4813
4750	4814	---	---

...	...	Solution to [%D %n (%T)](#problem:certificate)
4898	4962	~	~
4899	4963
4900	4964	The solution can be read from the following code:	The solution can be read from the following code:
4901
4902		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Certificate.sql}
4903		```
	4965
	4966		<!-- Bug, this code should be indented to be in the current environment. -->
	4967
	4968
	4969		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Certificate.sql}
	4970		```
4904	4971
4905	4972
4906	4973	---	---

...	...	Solution to [%D %n (%T)](#problem:sqlWorks)
4926	4993
4927	4994	The solution to the next questions can be read from the following code:	The solution to the next questions can be read from the following code:
4928	4995
4929
4930		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Work.sql snippet=solution}
4931		```
4932
4933		@problem:sqlWorks -- Solution to Q. -.#
4934		~
4935
4936		Finally, to answer the last question, here is a list of the possible limitations:
4937
4938		#. Having the name or the title as a primary key (in the `AUTHOR` and `WORK` tables) is not a good idea: we cannot have two authors with the same name or two pieces of work with the same title!
4939		#. If all the attributes in the `BOOK` and the `EBOOK` tables are going to be the same, then we should probably have only one table called `PUBLICATION` with a boolean to indicate whenever the publication is digital or on paper.
4940		#. Having a mix of `ON DELETE CASCADE` and `ON DELETE RESTRICT` is not really justified and makes the tables harder to use. We should have used the same update policy on both tables.
4941
	4996		<!-- Bug, this code should be indented to be in the current environment. -->
	4997
	4998
	4999		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_Work.sql snippet=solution}
	5000		```
	5001
	5002		@problem:sqlWorks -- Solution to Q. -.#
	5003		~
	5004
	5005		Finally, to answer the last question, here is a list of the possible limitations:
	5006
	5007		#. Having the name or the title as a primary key (in the `AUTHOR` and `WORK` tables) is not a good idea: we cannot have two authors with the same name or two pieces of work with the same title!
	5008		#. If all the attributes in the `BOOK` and the `EBOOK` tables are going to be the same, then we should probably have only one table called `PUBLICATION` with a boolean to indicate whenever the publication is digital or on paper.
	5009		#. Having a mix of `ON DELETE CASCADE` and `ON DELETE RESTRICT` is not really justified and makes the tables harder to use. We should have used the same update policy on both tables.
	5010
4942	5011	---	---
4943	5012
4944	5013	Solution to [%D %n (%T)](#problem:project1)	Solution to [%D %n (%T)](#problem:project1)
4945	5014	~	~
4946	5015	The answers can be found in the following snippet:	The answers can be found in the following snippet:
4947	5016
4948		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_TextbookAuthoredSol.sql snippet=solution}
4949		```
	5017		<!-- Bug, this code should be indented to be in the current environment. -->
	5018
	5019		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_TextbookAuthoredSol.sql snippet=solution}
	5020		```
4950	5021
4951	5022	---	---
4952	5023
4953	5024	Solution to [%D %n (%T)](#problem:project1bis)	Solution to [%D %n (%T)](#problem:project1bis)
4954	5025	~	~
4955	5026	The answers can be found in the following snippet:	The answers can be found in the following snippet:
4956
4957		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_CapstoneSol.sql snippet=solution}
4958		```
	5027
	5028		<!-- Bug, this code should be indented to be in the current environment. -->
	5029
	5030
	5031		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_CapstoneSol.sql snippet=solution}
	5032		```
4959	5033
4960	5034	---	---
4961	5035

...	...	Solution to [%D %n (%T)](#problem:residency)
5012	5086	@problem:residency -- Solution to Q. -.#	@problem:residency -- Solution to Q. -.#
5013	5087	~	~
5014	5088
5015		The answers can be found in the following snippet:
5016
5017		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ResidencySol.sql snippet=solution4}
5018		```
5019
5020		@problem:residency -- Solution to Q. -.#
5021		~
5022
5023	5089	The answers can be found in the following snippet:	The answers can be found in the following snippet:
5024	5090
5025		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ResidencySol.sql snippet=solution5}
5026		```
	5091		<!-- Bug, this code should be indented to be in the current environment. -->
5027	5092
5028		Note that the query that returns the name of the homeowners can be improved.
5029
5030		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ResidencySol.sql snippet=homonyms}
5031		```
	5093
	5094		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ResidencySol.sql snippet=solution4}
	5095		```
5032	5096
5033		@problem:residency -- Solution to Q. -.#
5034		~
5035
5036		To update the `SSN` of `"James Baldwin"` to `"000-00-0010"`, we could use:
5037
5038		```
5039		UPDATE PERSON SET SSN = "000-00-0010" WHERE FName = "James" AND LName = "Baldwin";
5040		```
	5097		@problem:residency -- Solution to Q. -.#
	5098		~
5041	5099
5042		However, this command would be rejected because of the foreign key constraint. On `UPDATE`, the foreign key from `RESIDENCY.Person` to `PERSON.SSN` restricts by default.
5043		The error would be:
5044		```
5045		ERROR 1451 (23000) at line 75: Cannot delete or update a parent row: a foreign key constraint fails (`HW_Residency_SOL`.`RESIDENCY`, CONSTRAINT `RESIDENCY_ibfk_1` FOREIGN KEY (`Person`) REFERENCES `PERSON` (`SSN`))
5046		```
	5100		The answers can be found in the following snippet:
5047	5101
5048		@problem:residency -- Solution to Q. -.#
5049		~
5050
5051		In our model, as it is currently,
5052
5053		#. It is possible for two people to have the same last name.
5054		#. It is possible for a person to have multiple principal residencies.
5055		#. It is not possible for a house to not be yellow.
5056		#. It is possible for the SSN to be any series of 11 characters.
5057		#. It is possible for a person to own any number of houses.
5058		#. It is possible for a person to rent any number of houses.
	5102		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ResidencySol.sql snippet=solution5}
	5103		```
5059	5104
5060		@problem:residency -- Solution to Q. -.#
5061		~
5062
5063		Considering the given state for the `RESIDENCY` table, the following two are possible primary keys:
5064
5065		#. `Person` and `PrincipalResidence`
5066		#. `Person` and `House`
	5105		Note that the query that returns the name of the homeowners can be improved.
5067	5106
5068		@problem:residency -- Solution to Q. -.#
5069		~
	5107		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ResidencySol.sql snippet=homonyms}
	5108		```
	5109
	5110		@problem:residency -- Solution to Q. -.#
	5111		~
	5112
	5113		To update the `SSN` of `"James Baldwin"` to `"000-00-0010"`, we could use:
	5114
	5115		```
	5116		UPDATE PERSON SET SSN = "000-00-0010" WHERE FName = "James" AND LName = "Baldwin";
	5117		```
	5118
	5119		However, this command would be rejected because of the foreign key constraint. On `UPDATE`, the foreign key from `RESIDENCY.Person` to `PERSON.SSN` restricts by default.
	5120		The error would be:
	5121		```
	5122		ERROR 1451 (23000) at line 75: Cannot delete or update a parent row: a foreign key constraint fails (`HW_Residency_SOL`.`RESIDENCY`, CONSTRAINT `RESIDENCY_ibfk_1` FOREIGN KEY (`Person`) REFERENCES `PERSON` (`SSN`))
	5123		```
	5124
	5125		@problem:residency -- Solution to Q. -.#
	5126		~
	5127
	5128		In our model, as it is currently,
	5129
	5130		#. It is possible for two people to have the same last name.
	5131		#. It is possible for a person to have multiple principal residencies.
	5132		#. It is not possible for a house to not be yellow.
	5133		#. It is possible for the SSN to be any series of 11 characters.
	5134		#. It is possible for a person to own any number of houses.
	5135		#. It is possible for a person to rent any number of houses.
	5136
	5137		@problem:residency -- Solution to Q. -.#
	5138		~
	5139
	5140		Considering the given state for the `RESIDENCY` table, the following two are possible primary keys:
5070	5141
5071		The first key would not accomodate a person with multiple secondary residencies, which is not a good thing.
5072		The second key could make sense, since it would refrain a person from declaring the same address twice as their residency.
5073		The only case that could be hard to work around is if a person was trying to own multiple units at the same address; however, this is more an issue with the primary key of `HOUSE` than an issue with the primary key we suggested for `RESIDENCY`.
	5142		#. `Person` and `PrincipalResidence`
	5143		#. `Person` and `House`
	5144
	5145		@problem:residency -- Solution to Q. -.#
	5146		~
	5147
	5148		The first key would not accomodate a person with multiple secondary residencies, which is not a good thing.
	5149		The second key could make sense, since it would refrain a person from declaring the same address twice as their residency.
	5150		The only case that could be hard to work around is if a person was trying to own multiple units at the same address; however, this is more an issue with the primary key of `HOUSE` than an issue with the primary key we suggested for `RESIDENCY`.
5074	5151
5075	5152
5076	5153	---	---

...	...	Solution to [%D %n (%T)](#problem:residency)
5078	5155	Solution to [%D %n (%T)](#problem:research-funding)	Solution to [%D %n (%T)](#problem:research-funding)
5079	5156	~	~
5080	5157	(Some of) the answers can be found in the following snippet:	(Some of) the answers can be found in the following snippet:
	5158		<!-- Bug, this code should be indented to be in the current environment. -->
	5159
5081	5160
5082		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ScientificResearchSol.sql snippet=solution}
5083		```
	5161		```{.sqlmysql .numberLines .includeLink include=code/sql/HW_ScientificResearchSol.sql snippet=solution}
	5162		```
5084	5163
5085	5164
5086	5165	# Designing a Good Database	# Designing a Good Database

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