31 SQL语句快速查询

以下是一些可以当工具书使用的参考语句，都是固定写法，需要的时候可以拿出来参考一下：

AND/OR 并且/或

SELECT column_name(s)
FROM table_name
WHERE condition
AND|OR condition;

 

ALTER TABLE 修改表

ALTER TABLE table_name
ADD column_name datatype
--或者
ALTER TABLE table_name
DROP COLUMN column_name;

 

AS（alisa） 重命名

备注：在英文中alisa是“化名、别名”的意思。

--对列名进行重命名
SELECT column_name AS column_alias
FROM table_name;

--对表进行重命名
SELECT column_name
FROM table_name AS table_alias;

 

BETWEEN...AND... 在某个区间

SELECT column_name(s)
FROM table_name
WHERE column_name
BETWEEN value1 AND value2;

 

CREATE DATABASE 创建数据库

CREATE DATABASE database_name;

 

CREATE TABLE 创建表

CREATE TABLE table_name
(
column_name1 data_type,
column_name2,data_type,
column_name3,data_type,
...
);

 

CREATE INDEX 创建索引

--创建普通索引
CREATE INDEX index_name
ON table_name (column_name);

--创建唯一索引
CREATE UNIQUE INDEX index_name
ON table_name (column_name);

 

CREATE VIEW 视图

CREATE VIEW view_name AS
SELECT column_name(s)
FROM table_name
WHERE condition;

 

DELETE 删除

--带条件的删除
DELETE FROM table_name
WHERE some_column=some_value;

--不带条件的删除
DELETE FROM table_name;

 

DROP DATABASE 删除数据库

DROP DATABASE database_name;

 

DROP INDEX 删除索引

--SQL Server的写法
DROP INDEX table_name.index_name;

--DB2/Oracle的写法
DROP INDEX index_name;

--MySQL的写法
ALTER TABLE table_name
DROP INDEX index_name;

 

DROP TABLE 删除表

DROP TABLE table_name;

 

GROUP BY 分组

SELECT column_name,aggregate_function(column_name)
FROM table_name
WHERE column_name operator value
GROUP BY column_name;

 

HAVING 分组过滤条件

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 在某些固定值中查找

SELECT column_name(s)
FROM table_name
WHERE column_name
IN (value1,value2,...);

 

 INSERT INTO 插入表

INSERT INTO table_name
VALUES (value1,value2,value3,...);
--或者
INSERT INTO table_name
(column1,column2,column3,...)
VALUES (value1,value2,value3,...);

 

INNER JOIN 内连接

SELECT column_name(s)
FROM table_name1
INNER JOIN table_name2
ON table_name1.column_name=table_name2.column;

 

LEFT JOIN 左连接

SELECT column_name(s)
FROM table_name1
LEFT JOIN table_name2
ON table_name1.column_name=table_name2.column_name;

 

RIGHT JOIN 右连接

SELECT column_name(s)
FROM table_name1
RIGHT JOIN table_name2
ON table_name1.column_name=table_name2.column_name;

 

FULL JOIN 全连接

SELECT column_name(s)
FROM table_name1
FULL JOIN table_name2
ON table_name1.column=table_name2.column_name;

 

LIKE 模糊

SELECT column_name(s)
FROM table_name
WHERE column_name LIKE pattern;

 

ORDER BY 排序

SELECT column_name(s)
FROM table_name
ORDER BY column_name [ASC|DESC];

 

SELECT 查找

SELECT column_name(s)
FROM table_name;

 

SELECT * 查找表的所有字段

SELECT *
FROM table_name;

 

SELECT DISTINCT 查找去除重复的列

SELECT DISTINCT column_name(s)
FROM table_name;

 

SELECT INTO 查询结果插入表

SELECT *
INTO new_table_name [IN externaldatabase]
FROM old_table_name;
--或者
SELECT column_name(s)
INTO new_table_name [IN externaldatabase]
FROM old_table_name;

 

SELECT TOP 查询前N条记录

SELECT TOP number|percent column_name(s)
FROM table_name;

 

TRUNCATE TABLE 清空表

TRUNCATE TABLE table_name;

 

UNION ALL 去重并集

SELECT coulmn_nams(s) FROM table_name1
UNION
SELECT column_nams(s) FROM table_name2;

 

UNION ALL 不去重并集

SELECT column_name(s) FROM table_name1
UNION ALL
SELECT column_name(s) FROM table_name2;

 

UNDATE 更新

UPDATE table_name
SET column1=value1,column2=value2
WHERE some_column=some_value;

 

WHERE 条件过滤

SELECT column_nams(s)
FROM table_name
WHERE column_name operator value;