增

增加一条数据

insert into table_name ( field1, field2,...fieldN )
                       values
                       ( value1, value2,...valueN )

如果数据是字符型，必须使用单引号或者双引号，如："value"。

删

删除一条数据

delete from table_name [where Clause]

如果没有指定 WHERE 子句，MySQL 表中的所有记录将被删除。

改

更新一条数据

UPDATE table_name SET field1=new-value1, field2=new-value2
[WHERE Clause]

查

查询关键字的定义顺序

SELECT DISTINCT <select_list>
FROM <left_table>
<join_type> JOIN <right_table>
ON <join_condition>
WHERE <where_condition>
GROUP BY <group_by_list>
HAVING <having_condition>
ORDER BY <order_by_condition>
LIMIT <limit_number>