MySQL-select查询

-- 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;