AND / OR
AND & OR 运算符用于基于一个以上的条件对记录进行过滤。
语法：SELECT column_name(s) FROM table_name WHERE condition AND|OR condition;
选择count大于10 且 count小于230
SELECT * FROM access_log WHERE count > 10 AND count < 230
选择count小于10 或 count大于230
SELECT * FROM access_log WHERE count < 10 OR count > 230
ALTER TABLE
ALTER TABLE 语句用于在已有的表中添加、删除或修改列。
语法：
// 添加一列
ALTER TABLE table_name
ADD column_name datatype
// 删除一列
ALTER TABLE table_name
DROP COLUMN column_name
// 更改一列字段类型
ALTER TABLE table_name
MODIFY COLUMN column_name VARCHAR(10)
// 更改一列
ALTER TABLE table_name
CHANGE COLUMN column_name re_name
AS (alias)
SELECT column_name AS column_alias
FROM table_name
OR
SELECT column_name
FROM table_name AS table_alias
对url改名为ii
SELECT url AS ii FROM websites
BETWEEN
语法：
SELECT column_name(s)
FROM table_name
WHERE column_name
BETWEEN value1 AND value2
选择alexa1到10的所有记录
SELECT * FROM websites WHERE alexa BETWEEN 1 AND 10
CREATE DATABASE
语法：CREATE DATABASE database_name
创建IIII数据库
CREATE DATABASE IIII
DROP DATABASE
语法：DROP DATABASE database_name
删除IIII数据库
DROP DATABASE IIII
CREATE TABLE
语法：
CREATE TABLE table_name (
column_name data_type,
column_name data_type,
...
)
创建一个名为 sds 的表，且有字段int
CREATE TABLE sds (id int)
DROP TABLE
语法：DROP TABLE IF EXISTS tabale_name
如果表sds存在就删除
DROP TABLE IF EXISTS sds
CREATE INDEX
创建索引
语法：
CREATE INDEX index_name
ON tabale_name (column_name)
OR
CREATE UNIQUE INDEX index_name
ON tabale_name (column_name)
CREATE VIEW
创建视图
视图是基于 SQL 语句的结果集的可视化的表。
语法：
CREATE VIEW view_name AS
SELECT column_name(s)
FROM tabale_name
DELETE
DELETE FROM tabale_name
WHERE some_column = some_value
OR
DELETE FROM tabale_name // 删除整个表
DELETE * FROM tabale_name
DROP DATABASE
删除数据库
DROP DATABASE data_name
DROP INDEX
删除索引
DROP INDEX index_name
DROP TABLE
删除表
DROP TABLE table_name
GROUP BY
合计函数 (比如 SUM) 常常需要添加 GROUP BY 语句。
SELECT column_name, aggregate_function(column_name)
FROM table_name
WHERE column_name operator value1
GROUP BY column_name
HAVING
在 SQL 中增加 HAVING 子句原因是，WHERE 关键字无法与合计函数一起使用。
SELECT column_name, aggregate_function(column_name)
FROM tabale_name
WHERE column_name operator value
GROUP BY column_name
HAVING aggregate_function(column_name) operator value
IN
IN 操作符允许您在 WHERE 子句中规定多个值。
SELECT column_name(s)
FROM tabale_name
WHERE column_name
IN(value1, value2)
INSERT INTO
插入数据
INSERT INTO tabale_name
VALUES(value1, value2, ...value3)
OR
INSERT INTO tabale_name
(column1, column2, ...column3)
VALUES(value1, value2, ...value3)
INNER JOIN
在表中存在至少一个匹配时，INNER JOIN 关键字返回行。
SELECT column_name(s)
FROM tabale_name1
INNER JOIN tabale_name2
ON tabale_name1.column_name = tabale_name2.column_name
LEFT JOIN
返回左表
SELECT column_name(s)
FROM tabale_name1
LEFT JOIN tabale_name2
ON tabale_name1.column_name = tabale_name2.column_name
RIGHT JOIN
返回左表
SELECT column_name(s)
FROM tabale_name1
RIGHT JOIN tabale_name2
ON tabale_name1.column_name = tabale_name2.column_name
FULL JOIN
只要其中某个表存在匹配，FULL JOIN 关键字就会返回行。
SELECT column_name(s)
FROM tabale_name1
FULL JOIN tabale_name2
ON tabale_name1.column_name = tabale_name2.column_name
LIKE
LIKE 操作符用于在 WHERE 子句中搜索列中的指定模式。
SELECT column_name(s)
FROM tabale_name
WHERE column_name LIKE pattern
ORDER BY
ORDER BY 语句用于对结果集进行排序。
SELECT column_name
FROM table_name
ORDER BY column_name[ASC|DESC]
SELECT
查询
SELECT column_name(s)
FROM tabale_name
SELECT *
SELECT *
FROM tabale_name
SELECT DISTINCT
关键词 DISTINCT 用于返回唯一不同的值。
SELECT DISTINCT column_name(s)
FROM tabale_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 column_name(s)
FROM table_name
LIMIT number
TRUNCATE TABLE
TRUNCATE TABLE table_name
UNION
SQL UNION 操作符合并两个或多个 SELECT 语句的结果。
SELECT column_name(s) FROM tabale_name1
UNION
SELECT column_name(s) FROM tabale_name2
UNION ALL
SELECT column_name(s) FROM tabale_name1
UNION ALL
SELECT column_name(s) FROM tabale_name2
UPDATE
更新
UPDATE tabale_name
SET column1=value, column2=value
WHERE some_column=some_value
WHERE
条件
SELECT column_name(s)
FROM tabale_name
WHERE column_name operator value
参考文档
SQL文档
