sql关键字太多，偶尔会忘记怎么用，记录整理一下，需要的时候打开复习一波。

 

SQL 语句

语法

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 DATABASE

CREATE DATABASE database_name

CREATE TABLE

CREATE TABLE table_name

(

column_name1 data_type,

column_name2 data_type,

column_name2 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

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