SQL Cheat Sheet

in #sql • 7 years ago

SQL can do a lot: data insertion, querying, updating and deleting, schema creation and modification, and data access control. I have to look up this stuff more often than I'd like to admit. How do I alter a column again? How do I insert into another table from this table? How do I group by?

Here is a cheat sheet (mostly for my personal reference).

ヽ༼ຈ ل͜ ຈ༽ﾉ

Statement Syntax
AND / OR SELECT column_name(s)
FROM table_name
WHERE condition
AND|OR condition
ALTER TABLE ALTER TABLE table_name
ADD column_name datatype

or

ALTER TABLE table_name
DROP COLUMN column_name
AS (alias) SELECT column_name AS column_alias
FROM table_name

or

SELECT column_name
FROM table_name  AS table_alias
BETWEEN SELECT column_name(s)
FROM table_name
WHERE column_name
BETWEEN value1 AND value2
CREATE DB CREATE DATABASE database_name
CREATE TABLE CREATE TABLE table_name
(
column_name1 data_type,
column_name2 data_type,
column_name3 data_type,
...
)
CREATE INDEX CREATE INDEX index_name
ON table_name (column_name)

or

CREATE UNIQUE INDEX index_name
ON table_name (column_name)
CREATE VIEW CREATE VIEW view_name AS
SELECT column_name(s)
FROM table_name
WHERE condition
DELETE DELETE FROM table_name
WHERE some_column=some_value

or

DELETE FROM table_name
(Note: Deletes the entire table!!)

DELETE * FROM table_name
(Note: Deletes the entire table!!)
DROP DATABASE DROP DATABASE database_name
DROP INDEX DROP INDEX table_name.index_name (SQL Server)
DROP INDEX index_name ON table_name (MS Access)
DROP INDEX index_name (DB2/Oracle)
ALTER TABLE table_name
DROP INDEX index_name (MySQL)
DROP TABLE DROP TABLE table_name
EXISTS IF EXISTS (SELECT * FROM table_name WHERE id = ?)
BEGIN
--do what needs to be done if exists
END
ELSE
BEGIN
--do what needs to be done if not
END
GROUP BY SELECT column_name, aggregate_function(column_name)
FROM table_name
WHERE column_name operator value
GROUP BY column_name
HAVING SELECT column_name, aggregate_function(column_name)
FROM table_name
WHERE column_name operator value
GROUP BY column_name
HAVING aggregate_function(column_name) operator value
IN SELECT column_name(s)
FROM table_name
WHERE column_name
IN (value1,value2,..)
INSERT INTO INSERT INTO table_name
VALUES (value1, value2, value3,....)

or

INSERT INTO table_name
(column1, column2, column3,...)
VALUES (value1, value2, value3,....)
INNER JOIN SELECT column_name(s)
FROM table_name1
INNER JOIN table_name2
ON table_name1.column_name=table_name2.column_name
LEFT JOIN SELECT column_name(s)
FROM table_name1
LEFT JOIN table_name2
ON table_name1.column_name=table_name2.column_name
RIGHT JOIN SELECT column_name(s)
FROM table_name1
RIGHT JOIN table_name2
ON table_name1.column_name=table_name2.column_name
FULL JOIN SELECT column_name(s)
FROM table_name1
FULL JOIN table_name2
ON table_name1.column_name=table_name2.column_name
LIKE SELECT column_name(s)
FROM table_name
WHERE column_name LIKE pattern
ORDER BY SELECT column_name(s)
FROM table_name
ORDER BY column_name [ASC|DESC]
SELECT SELECT column_name(s)
FROM table_name
SELECT * SELECT *
FROM table_name
SELECT DISTINCT SELECT DISTINCT column_name(s)
FROM table_name
SELECT INTO SELECT *
INTO new_table_name [IN externaldatabase]
FROM old_table_name

or

SELECT column_name(s)
INTO new_table_name [IN externaldatabase]
FROM old_table_name
SELECT TOP SELECT TOP number|percent column_name(s)
FROM table_name
TRUNCATE TABLE TRUNCATE TABLE table_name
UNION SELECT column_name(s) FROM table_name1
UNION
SELECT column_name(s) FROM table_name2
UNION ALL SELECT column_name(s) FROM table_name1
UNION ALL
SELECT column_name(s) FROM table_name2
UPDATE UPDATE table_name
SET column1=value, column2=value,...
WHERE some_column=some_value
WHERE SELECT column_name(s)
FROM table_name
WHERE column_name operator value

(▀̿Ĺ̯▀̿ ̿)

#databases
7 years ago in #sql by
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