MySQL Select-distinct

Distinct:

去掉重复记录.

所有显示出的（可以不用* ，加字段显示）字段的值都相同才会显示其中一条。

语法：

Select distinct * from tbl_name;

*  (可以换成字段名称来显示某一些字段)

 

与之对应的是 all，表示所有，默认值

/*简单示例*/
use php_one;

create table t12(
a int
);

insert into t12 values(5);
insert into t12 values(10);
insert into t12 values(1);
insert into t12 values(15);
insert into t12 values(7);
insert into t12 values(8);
insert into t12 values(15);
insert into t12 values(50);
insert into t12 values(3);
insert into t12 values(1);
insert into t12 values(50);
insert into t12 values(35);

select * from t12;
select * from t12 order by a;
select distinct * from t12 order by a ; /*消去重复的*/