基本SQL语句总结

 

基本操作	基本语句
查询user表所有数据	select * from user
查询user表中name字段所有数据	select name from user
查询user表中符合条件的所有name字段	select name from user where password in (A,B,C)
增加一条数据	insert into user (id,name,passowrd) values (1,Harrych,1994)
删除一条数据	delete from user where id=1
修改一条数据	update user set name=Harry where id=1
分页查询	select * from user limit #{page},#{offset}
分页排序查询	select * from user where 1=1 order by time desc limit #{page},#{offset}
查询最前面2行数据	select top 2 * from user
like查询 (%代表缺少的字符）	select * from user where name like 'h%'
"_"通配符查询（_代表缺少的一个字母）	select * from user where name like '_on'
查询name以H,C开头的数据	select * from user where name like '[HC]%'
查询name不以H,C开头的数据	select * from user where name like '[!HC]%'
查询指定范围的数据（左包右不包）	select * from user where name between 'A' and 'B'
查询指定范围外的数据	select * from user where name not between 'A' and 'B'
指定别名查询	select * from user u where u.name='chen' and u.name='cao' and u.name='shi'
多表联查（user表，person表）	select user.name,person.name from person,user where person.id=user.id
join 内连接多表联查	select user.name,person.name from user inner join orders on user.id=person.id order by user.name
join 左连接多表查询	select user.name,person.name where user left join person on user.id=person.id order by user.name
join 右连接多表查询	select user.name,person.name where user right join person on user.id=person.id order by user.name
join 全连接多表查询	select user.name,person.name where user full join person on user.id=person.id
多表合并查询（返回所有数据，包括重复的）	select name from user union all select name from person
多表合并查询（返回不重复的数据）	select name from user union select name from person
从一个表将指定数据插入到另一个表	select * into new_user from user
将另一个数据库的user表数据插入到user表中	select * into user in 'aa.mdb' from user
查询表中某个字段最大值,取名为max_id	select max(id) max_id from user
查询表中某个字段最小值	select min(id) from user
查询表中最后一行某个字段的值	select last(name) from user
查询表中第一行某个字段的值	select first(name) from user
查询表中某个字段的列总和	select sum(id) from user
查询所有不同name的在表中某个字段的总数量	select name,sum(id) from user group by name
查询所有不同name的在表中某个字段的总数量	select name,sum(id) from user group by name having sum(id)<200
将name字段的值改成大写	select ucase(name) as name,password from user
将name字段的值改成小写	select lcase(name) as name,password from user
从name字段中提取前三个字符	select mid(name,1,3) as name from user
获取name字段长度	select len(name) from user
将A表中price舍去小数位	select round(price,0) as price from A
获取当前数据库时间	select now() from user
格式化查询的数据	select name ,price, format(now(),'YYYY-MM-DD') as now_time from A