-- 查询表的所有信息 -- select * from 表名 select * from sys_user; -- 查询指定字段 -- select 字段1, 字段2, ... from 表名 select name, age, sex from sys_user; -- 去重:根据选中的字段去重 -- select distinct 字段1, 2, ... from 表名 select distinct sex from sys_user; -- 查询条件 -- select 字段 -- from 表名 -- where 条件 select * from sys_user where sex = 'male'; select * from sys_user where name = 'Jack' and age = 22; -- 条件模糊查询:like select * from sys_user where name like 'J%'
-- order by 排序查询:asc默认升序查询,desc降序插叙 -- select 字段 from 表名 order by 排序字段 [asc/desc] select * from sys_user order by age desc;