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
pinpai cnt Audi 2 BMW 1 Lambo 2 Toyota 1
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
pinpai cnt Audi 2 BMW 1 Lambo 2 Toyota 1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
pinpai cnt 4 6
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
pinpai cnt 4 6
你是一点数据库知识都不学?

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