如何在MySQL中仅命令一次返回重复的列值？

要在MySQL中仅返回一次列值，我们首先来看一个示例并创建一个表-

create table DemoTable680(Status varchar(100));

使用插入命令在表中插入一些记录-

insert into DemoTable680 values(Busy); insert into DemoTable680 values(At Work); insert into DemoTable680 values(Busy); insert into DemoTable680 values(Blocked); insert into DemoTable680 values(Offline); insert into DemoTable680 values(Offline); insert into DemoTable680 values(Blocked);

使用select语句显示表中的所有记录-

select *from DemoTable680;

这将产生以下输出-

+---------+ | Status | +---------+ | Busy | | At Work | | Busy | | Blocked | | Offline | | Offline | | Blocked | +---------+ 7 rows in set (0.00 sec)

以下是在MySQL中仅返回一次重复列值的查询-

select distinct Status from DemoTable680 order by Status;

这将产生以下输出-

+---------+ | Status | +---------+ | At Work | | Blocked | | Busy | | Offline | +---------+ 4 rows in set (0.00 sec)