mysql 统计每天每个列的合计值数值紧急

select date_format(结账时间,'%Y-%m-%d'),sum(收入),sum(支付金额),count(*)

from 营业情况

where 结账时间 >='2012-07-02' and 结账时间 <'2012-08-03'

group by date_format(结账时间,'%Y-%m-%d')

select * from salers s1,sales s2 where s1.id = s2.salers_id

select * from salers s1 left join sales s2 on s1.id = s2.salers_id

select * from salers s1 where s1.id in (select s2.salers_id from sales s2)

你没发表结构，我猜了几种你先看看

您好，单个select语句实现MySQL查询统计次数的方法用处在哪里呢？用处太多了，比如一个成绩单，你要查询及格得人数与不及格的人数，怎么一次查询出来？

MySQL查询统计次数简单的语句肯定是这样了：

select a.name,count_neg,count_plus from

(select count(id) as count_plus,name from score2 where score >=60 group by name) a,

(select count(id) as count_neg,name from score2 where score <=60 group by name) b

where a.name=b.name

即必须至少用2个语句。

今天刚好碰到发现mysql支持if，那就创造性的用if来实现吧：

select name, sum(if(score>=60,1,0)),sum(if(score<60,1,0)) from score2 group by name

单个select语句实现MySQL查询统计次数的方法简单吧。

原理就是大于60，就赋值为1，那么sum就是计数了。

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