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IntroSQL_Presentation.sql
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/* SELECT Clause */
SELECT 1, 2, 'this is a string', 1/2;
SELECT 1, 2, 'this is a string', 1/2, 4/2, 5/2, 1/2., 1./2, 1/CAST(2 AS FLOAT);
/* The following two statements produce the same table. */
SELECT 1, 2, 'this is a string', 1/2;
SELECT 1,
2,
'this is a string', 1/2;
/* SQL Functions */
SELECT ABS(-8), LENGTH('This is a String'), LOWER('ThIS Is A StRiNg'), RANDOM();
/* FROM Clause */
SELECT name, type, start_time, end_time, location
FROM event;
/* Aggregate Functions */
SELECT COUNT( 12 ), COUNT('ssdf'), COUNT(NULL), SUM(23), SUM(0), SUM(NULL),
AVG(0), AVG(NULL);
SELECT COUNT(*), COUNT(string), COUNT(floating), AVG(number), SUM(number),
GROUP_CONCAT(string, ' ')
FROM example;
/* DISTINCT */
SELECT DISTINCT event
FROM attendance;
/* Aliases */
SELECT COUNT(*) AS num_rows, COUNT(string) AS num_strings,
COUNT(floating) AS num_float, AVG(number) AS avg_integer,
SUM(number) AS sum_int, GROUP_CONCAT(string, ' ') AS cat_string
FROM example;
/* WHERE Clause */
SELECT name, type, start_time, end_time, location
FROM event
WHERE type = 'social';
/* LIKE Prediate */
SELECT *
FROM member
WHERE name LIKE 'F%';
/* AND, OR Operators */
SELECT name
FROM member
WHERE name LIKE '_a%' OR name LIKE '%b';
/* GROUP BY Clause */
SELECT type, COUNT(*) AS num_events
FROM event
GROUP BY type;
/* HAVING Clause */
SELECT faculty, major, COUNT(*)
FROM member
GROUP BY faculty, major
HAVING COUNT(*) >= 2;
/* GROUP BY WITH ROLLUP/CUBE not implemented in SQLite */
/* CROSS JOIN */
SELECT m1.name AS Player_1, m2.name AS Player_2
FROM member AS m1 CROSS JOIN member AS m2;
SELECT m1.name AS Player_1, m2.name AS Player_2
FROM member AS m1 CROSS JOIN member AS m2
WHERE m1.name > m2.name;
/* INNER JOIN */
SELECT m1.name AS Player_1, m2.name AS Player_2
FROM member AS m1 INNER JOIN member AS m2 ON m1.name > m2.name;
SELECT at.name, at.faculty, at.major, COUNT(a.event) AS events_attended
FROM (member AS m INNER JOIN attendance AS a ON m.quest_id = a.member) AS at
GROUP BY at.quest_id, at.name, at.faculty, at.major
ORDER BY events_attended;
/* OUTER JOIN */
SELECT at.name, at.faculty, at.major, COUNT(a.event) AS events_attended
FROM (member AS m LEFT OUTER JOIN attendance AS a ON m.quest_id = a.member) AS at
GROUP BY at.quest_id, at.name, at.faculty, at.major
ORDER BY events_attended;
/* NATURAL JOIN */
SELECT e.name, e.position, ep.duties
FROM exec AS e NATURAL JOIN exec_position AS ep;
/* Non-Correlated Subquery */
SELECT e.name, e.position
FROM exec AS e
WHERE e.questid IN (SELECT poster FROM event);
/* Correlated Subquery */
SELECT name, position,
(SELECT faculty FROM member AS m WHERE m.quest_id = e.questid) AS faulty,
(SELECT major FROM member AS m WHERE m.quest_id = e.questid) AS major
FROM exec AS e;
/* UNION set Operation */
SELECT name, email, NULL AS phone
FROM member
UNION
SELECT name, email, phone
FROM exec;
/* Intersection set Operation */
SELECT name, quest_id
FROM member
INTERSECT
SELECT name, questid
FROM exec;
/* Difference set Operation */
SELECT name, quest_id
FROM member
EXCEPT
SELECT name, questid
FROM exec;
/* WITH Clause */
WITH cost (event, expenses) AS
(SELECT event, SUM(price)
FROM expenses
GROUP BY event)
SELECT e.name, e.type, e.budget, cost.expenses
FROM event AS e INNER JOIN cost ON e.name = cost.event;
/* CASE Expressions */
WITH cost (event, expenses) AS
(SELECT event, SUM(price)
FROM expenses
GROUP BY event)
SELECT e.name, e.type, e.budget, cost.expenses,
CASE
WHEN e.budget - cost.expenses < 0 THEN 'Over budget'
ELSE NULL
END AS warning
FROM event AS e INNER JOIN cost ON e.name = cost.event;
/* ORDER BY Clause */
SELECT name
FROM member
ORDER BY name;
/* LIMIT Clause */
SELECT name
FROM member
ORDER BY name
LIMIT 10;
/* GROUP BY Clause */
SELECT type, COUNT(*) AS num_events
FROM event
GROUP BY type;
/* HAVING Clause */
SELECT faculty, major, COUNT(*)
FROM member
GROUP BY faculty, major
HAVING COUNT(*) >= 2;
/* GROUP BY WITH ROLLUP/CUBE not implemented in SQLite */
/* CROSS JOIN */
SELECT m1.name AS Player_1, m2.name AS Player_2
FROM member AS m1 CROSS JOIN member AS m2;
SELECT m1.name AS Player_1, m2.name AS Player_2
FROM member AS m1 CROSS JOIN member AS m2
WHERE m1.name > m2.name;
/* INNER JOIN */
SELECT m1.name AS Player_1, m2.name AS Player_2
FROM member AS m1 INNER JOIN member AS m2 ON m1.name > m2.name;
SELECT at.name, at.faculty, at.major, COUNT(a.event) AS events_attended
FROM (member AS m INNER JOIN attendance AS a ON m.quest_id = a.member) AS at
GROUP BY at.quest_id, at.name, at.faculty, at.major
ORDER BY events_attended;
/* OUTER JOIN */
SELECT at.name, at.faculty, at.major, COUNT(a.event) AS events_attended
FROM (member AS m LEFT OUTER JOIN attendance AS a ON m.quest_id = a.member) AS at
GROUP BY at.quest_id, at.name, at.faculty, at.major
ORDER BY events_attended;
/* NATURAL JOIN */
SELECT e.name, e.position, ep.duties
FROM exec AS e NATURAL JOIN exec_position AS ep;
/* Non-Correlated Subquery */
SELECT e.name, e.position
FROM exec AS e
WHERE e.questid IN (SELECT poster FROM event);
/* Correlated Subquery */
SELECT name, position,
(SELECT faculty FROM member AS m WHERE m.quest_id = e.questid) AS faulty,
(SELECT major FROM member AS m WHERE m.quest_id = e.questid) AS major
FROM exec AS e;
/* UNION set Operation */
SELECT name, email, NULL AS phone
FROM member
UNION
SELECT name, email, phone
FROM exec;
/* Intersection set Operation */
SELECT name, quest_id
FROM member
INTERSECT
SELECT name, questid
FROM exec;
/* Difference set Operation */
SELECT name, quest_id
FROM member
EXCEPT
SELECT name, questid
FROM exec;
/* WITH Clause */
WITH cost (event, expenses) AS
(SELECT event, SUM(price)
FROM expenses
GROUP BY event)
SELECT e.name, e.type, e.budget, cost.expenses
FROM event AS e INNER JOIN cost ON e.name = cost.event;
/* CASE Expressions */
WITH cost (event, expenses) AS
(SELECT event, SUM(price)
FROM expenses
GROUP BY event)
SELECT e.name, e.type, e.budget, cost.expenses,
CASE
WHEN e.budget - cost.expenses < 0 THEN 'Over budget'
ELSE NULL
END AS warning
FROM event AS e INNER JOIN cost ON e.name = cost.event;
/* ORDER BY Clause */
SELECT name
FROM member
ORDER BY name;
/* LIMIT Clause */
SELECT name
FROM member
ORDER BY name
LIMIT 10;