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>