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>