SQL 快速参考



来自 W3School 的 SQL 快速参考。可以打印它,以备日常使用。


SQL 语句

语句

语法

AND / OR

SELECT column_name(s)

FROM table_name

WHERE condition

AND|OR condition

ALTER TABLE (add column)

ALTER TABLE table_name 

ADD column_name datatype

ALTER TABLE (drop column)

ALTER TABLE table_name 

DROP COLUMN column_name

AS (alias for column)

SELECT column_name AS column_alias

FROM table_name

AS (alias for table)

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 DATABASE

CREATE DATABASE database_name

CREATE INDEX

CREATE INDEX index_name

ON table_name (column_name)

CREATE TABLE

CREATE TABLE table_name

(

column_name1 data_type,

column_name2 data_type,

.......

)

CREATE UNIQUE INDEX

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 FROM

DELETE FROM table_name 

(Note: Deletes the entire table!!)

or

DELETE FROM table_name
WHERE condition

DROP DATABASE

DROP DATABASE database_name

DROP INDEX

DROP INDEX table_name.index_name

DROP TABLE

DROP TABLE table_name

GROUP BY

SELECT column_name1,SUM(column_name2)

FROM table_name

GROUP BY column_name1

HAVING

SELECT column_name1,SUM(column_name2)

FROM table_name

GROUP BY column_name1

HAVING SUM(column_name2) condition value

IN

SELECT column_name(s)

FROM table_name

WHERE column_name

IN (value1,value2,..)

INSERT INTO

INSERT INTO table_name

VALUES (value1, value2,....)

or

INSERT INTO table_name
(column_name1, column_name2,...)
VALUES (value1, value2,....)

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

(used to create backup copies of tables)

SELECT *

INTO new_table_name

FROM original_table_name

or

SELECT column_name(s)
INTO new_table_name
FROM original_table_name

TRUNCATE TABLE

(deletes only the data inside the table)

TRUNCATE TABLE table_name

UPDATE

UPDATE table_name

SET column_name=new_value

[, column_name=new_value]

WHERE column_name=some_value

WHERE

SELECT column_name(s)

FROM table_name

WHERE condition