PHP mysql如何查询某个字段有多少个不同的值-PHP 튜토리얼-php.cn

PHP mysql如何查询某个字段有多少个不同的值

WBOY

풀어 주다： 2016-06-23 13:01:57

원래의

1687명이 탐색했습니다.

举个例子，
在car表有个pinpai字段，
有Lambo，Audi，BMW，Audi，Toyota，Lambo 6个值，
那么这个字段有4个不同的品牌，6辆车
求解如何得出4这个值和6这个值
前台显示的是："现共有4种品牌车辆，共计6辆。"
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求大神给个完整的sql select语句本人新手求实力老司机指点
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不要复制粘贴
select pinpai from car group by pinpai 和 select distinct pinpai from car
不是我要的答因为他们之中缺少数量

回复讨论(解决方案)

create temporary table car (pinpai varchar(10));insert into car values ('Lambo'),('Audi'),('BMW'),('Audi'),('Toyota'),('Lambo');select pinpai, count(*) as cnt from car group by 1

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pinpai cnt Audi   2 BMW    1 Lambo  2 Toyota 1

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你没有理解我的意思，你这不是我要的结果，我是要显示前台显示的是："现共有4种品牌车辆，共计6辆。" 而不是把它们每个品牌有多少个显示出来

create temporary table car (pinpai varchar(10));insert into car values ('Lambo'),('Audi'),('BMW'),('Audi'),('Toyota'),('Lambo');select pinpai, count(*) as cnt from car group by 1

로그인 후 복사

pinpai cnt Audi   2 BMW    1 Lambo  2 Toyota 1

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你没有理解我的意思，你这不是我要的结果，我是要显示前台显示的是："现共有4种品牌车辆，共计6辆。" 而不是把它们每个品牌有多少个显示出来

使用group by + count(*)就可以了.

select pinpai, count(*) as num from car group by pinpai;

select count(*) pinpai, sum(cnt) as cnt  from (select pinpai, count(*) as cnt from car group by 1) T

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pinpai cnt 4      6

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你是一点数据库知识都不学？

select count(*) pinpai, sum(cnt) as cnt  from (select pinpai, count(*) as cnt from car group by 1) T

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pinpai cnt 4      6

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你是一点数据库知识都不学？