-- 9/24

tee 2024_9_24_sql_log.txt

use toyu;

SELECT StuId
FROM enroll;


SELECT DISTINCT StuId
FROM enroll;

SELECT DISTINCT d.deptCode, d.deptName AS department
FROM Department AS d
WHERE d.schoolCode = 'CSE';


SELECT DISTINCT d.deptCode, d.deptName AS department
WHERE d.schoolCode = 'CSE'
FROM Department AS d;



DROP SCHEMA IF EXISTS tinker;
CREATE SCHEMA tinker;
USE tinker;

CREATE TABLE s2
SELECT * FROM toyu.student;

CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name
    [(create_definition,...)]
    [table_options]
    [partition_options]
    [IGNORE | REPLACE]
    [AS] query_expression

SELECT *
FROM s2;

CREATE TEMPORARY TABLE s3
SELECT * FROM toyu.student;

SELECT *
FROM s3;

CREATE TABLE s4 LIKE toyu.student;

SELECT *
FROM s4;

INSERT INTO s4
SELECT * FROM toyu.student;

SELECT *
FROM s4;

SHOW TABLES;

-- Note that keys and constraints of student are missing in s2 and S3.
DESC toyu.student;
DESC s2;
DESC s3;
DESC s4;

DROP TABLE s2;
DROP TABLE s3;
DROP TABLE s4;

SHOW TABLES;

DROP SCHEMA IF EXISTS tinker;

UPDATE student
SET major = 'CSCI';

UPDATE student
SET major = 'CINF'
WHERE lname = 'Hawk';


-- operators:
-- student with credits in a range.
SELECT DISTINCT *
FROM Student
WHERE ach BETWEEN 30 AND 70;

SELECT DISTINCT *
FROM Student
WHERE ach >= 30 
AND ach <= 70;

-- student in selected majors
SELECT DISTINCT *
FROM Student
WHERE major IN ('CSCI', 'CINF', 'ITEC');

SELECT DISTINCT *
FROM Student AS s
WHERE EXISTS
(SELECT *  -- a subquery
FROM Enroll AS e
WHERE e.stuId = s.stuId);

SELECT DISTINCT s.*
FROM Student AS s INNER JOIN Enroll AS e USING (stuId);


SELECT DISTINCT s.*
FROM student AS s
WHERE s.lname LIKE '%k%';

SELECT 'Michael!' REGEXP '.*';

SELECT DISTINCT s.*
FROM student AS s
WHERE s.lname REGEXP '.*k.*';

SELECT DISTINCT s.*
FROM student AS s
WHERE s.lname REGEXP '.*[jkl].*';

SELECT DISTINCT s.fname, s.lname, c.classId, e.grade
FROM student AS s, enroll AS e, class AS c
WHERE s.stuId = e.stuId -- Join condition
AND e.classId = c.classId -- Join condition
AND c.semester = 'Fall' -- problem condition
AND c.year = 2019; -- problem condition


SELECT DISTINCT s.fname, s.lname, c.classId, e.grade
FROM student AS s INNER JOIN enroll e ON (s.stuId = e.stuId) -- Join condition
    INNER JOIN class AS c ON (e.classId = c.classId) -- Join condition
WHERE c.semester = 'Fall' -- Problem condition
AND c.year = 2019; -- Problem condition

SELECT DISTINCT s.fname, s.lname, c.classId, e.grade
FROM student AS s INNER JOIN enroll e USING (stuId) -- Join condition
    INNER JOIN class AS c USING (classId) -- Join condition
WHERE c.semester = 'Fall' -- Problem condition
AND c.year = 2019; -- Problem condition

SELECT DISTINCT CONCAT(s.fname, ' ', s.lname) AS student,
    d.deptName AS `minor department`
FROM student AS s INNER JOIN department AS d ON (s.minor = d.deptCode);

-- List the names of the students with their minors (in full name).
SELECT DISTINCT CONCAT(s.fname, ' ', s.lname) AS student,
    d.deptName AS `minor department`
FROM student AS s LEFT JOIN department AS d ON (s.minor = d.deptCode);

SELECT DISTINCT CONCAT(s.fname, ' ', s.lname) AS student,
    d.deptName AS `minor department`,
    d.numStaff
FROM student AS s LEFT JOIN department AS d ON (s.minor = d.deptCode);

SELECT DISTINCT CONCAT(s.fname, ' ', s.lname) AS student,
    IFNULL(d.deptName, 'Undeclared') AS `minor department`
FROM student AS s LEFT JOIN department AS d ON (s.minor = d.deptCode);

-- student within 60 credits of the maximum number of ach any student may have.
SELECT DISTINCT s.stuId,
   CONCAT(s.fname, ' ', s.lname) AS student,
   s.ach AS credits
FROM student AS s
WHERE s.ach + 60 >=
   (SELECT DISTINCT MAX(ach) FROM student);

-- subqueries as derived tables.
SELECT DISTINCT s.stuId,
   CONCAT(s.fname, ' ', s.lname) AS student,
   s.ach AS credits
FROM student AS s INNER JOIN
   (SELECT DISTINCT MAX(ach) AS max FROM student) AS m -- an alias is required.
WHERE s.ach + 60 >= m.max;

WITH m AS
(SELECT DISTINCT MAX(ach) AS max FROM student)
SELECT DISTINCT s.stuId,
   CONCAT(s.fname, ' ', s.lname) AS student,
   s.ach AS credits
FROM student AS s INNER JOIN m -- an alias is required.
WHERE s.ach + 60 >= m.max;


WITH  t1 AS
   (SELECT MAX(ach) AS max FROM student)
SELECT s.stuId,
   s.ach AS `ach credits`,
   t1.max - s.ach AS `diff from max credits of all`
FROM student AS s, t1
ORDER BY `ach credits` DESC;