Question

数据库架构看起来像

雇员（employee_name，街道，城市）
作品（employee_name，COMPANY_NAME，工资）
公司（COMPANY_NAME，市）
管理（employee_name，MANAGER_NAME）

需要做的查询是：
找到拥有最多员工的公司。

我可以通过查询找出最大数量：

SELECT max( cnt ) max_cnt
FROM (

SELECT count( employee_name ) cnt, company_name
FROM works
GROUP BY company_name
)w1;

但现在我找不到公司的名称。如果有人有想法请分享。

Answer 1

要获得包含最大值的整行，您可以使用ORDER BY ... DESC LIMIT 1代替MAX：

SELECT company_name, cnt
FROM (
    SELECT company_name, count(employee_name) AS cnt
    FROM works
    GROUP BY company_name
) w1
ORDER BY cnt DESC
LIMIT 1

Answer 2

如下：

SELECT count( employee_name ) cnt, company_name
FROM works
GROUP BY company_name
ORDER BY cnt DESC
LIMIT 1;

编辑：

上面修正了MySQL

Answer 3

SELECT company_name,count(*) as cnt 
FROM works 
GROUP BY company_name 
ORDER BY cnt DESC

Answer 4

select company_name 
from works
group by company_name
having count(distinct employee_name)>=all(select count(distinct employee_name)
from works
group by company_name )

Answer 5

这是工作查询

Select * from(SELECT count(EmpName)cnt, CName FROM works GROUP BY CName Order By cnt desc) where ROWNUM = 1;

Answer 6

这看起来像是课程问题。

如果不止一家公司拥有相同数量的员工，则LIMIT的查询无效。＆＃34; ORDER BY＆＃34;没有过滤掉无用的信息。因此，我们有以下解决方案

SELECT company_name FROM
(SELECT company_name, count(employee_name) cnt
    FROM works
    GROUP BY company_name) 
JOIN 
(SELECT max(cnt) max_cnt
FROM (
    SELECT count(employee_name) cnt
    FROM works
    GROUP BY company_name
)) ON cnt = max_cnt

Answer 7

select company_name from works_for
group by company_name
having count(employee_name) = (select max(count(employee_name))from works_for
group by company_name);

SQL查询max（），count（）

7 个答案: