SQL - 选择名称和其员工的最大数量各部门的地址

-1

部门

DEPARTMENT_ID DEPARTMENT_NAME  ADDRESS    
------------- -------------------- -------------------- 
     10 ACCOUNTING   NEW YORK    
     20 RESEARCH    DALLAS    
     30 SALES    CHICAGO    
     40 IT     DALLAS    
     50 EXECUTIVE   NEW YORK    
     60 MARKETING   CHICAGO

员工

Employee_ID employee_name job      manager_ID hire_date salary commission department_ID 
------------------------------------------------------------------------------------------------------------ 
7839  KING   PRESIDENT       20-NOV-01 5000    50 
7596  JOST   VICE PRESIDENT   7839  04-MAY-01 4500    50 
7603  CLARK   VICE PRESIDENT   7839  12-JUN-01 4000    50 
7566  JONES   PUBLIC ACCOUNTANT  7596  05-APR-01 3000    10 
7886  STEEL   PUBLIC ACCOUNTANT  7566  08-MAR-03 2500    10 
7610  WILSON   ANALYST     7596  03-DEC-01 3000    20 
7999  WOLFE   ANALYST     7610  15-FEB-02 2500    20 
7944  LEE    ANALYST     7610  04-SEP-06 2400    20 
7900  FISHER   SALESMAN    7603  06-DEC-01 3000 500   30 
7921  JACKSON   SALESMAN    7900  25-FEB-05 2500 400   30 
7952  LANCASTER  SALESMAN    7900  06-DEC-06 2000 150   30 
7910  SMITH   DATABASE ADMINISTRATOR 7596  20-DEC-01 2900    40 
7788  SCOTT   PROGRAMMER    7910  15-JAN-03 2500    40 
7876  ADAMS   PROGRAMMER    7910  15-JAN-03 2000    40 
7934  MILLER   PROGRAMMER    7876  25-JAN-02 1000    40 
8000  BREWSTER  TBA         22-AUG-13 2500

我需要显示除达拉斯外的名称和地址，拥有最多的员工人数。

我写了这个：

SELECT department_name, address 
FROM department 
WHERE department_id IN 
       (SELECT MAX(department_id) 
        FROM  department 
        WHERE UPPER(address) != 'DALLAS') 
ORDER BY department_name;

但我只得到一个行

DEPARTMENT_NAME  ADDRESS    
-------------------- -------------------- 
MARKETING   CHICAGO

我在做什么错？

来源

2015-09-18 user5352234

首先，为什么你不能获得单个记录？你在期待什么？其次，你为什么要做'MAX（department_id）'？你认为那是什么？ – sstan

所有你将会得到的是一行，因为你说的部门ID匹配最大部门ID。所以，最高价值的部门ID。您需要使用“有数”的组。 – CargoMeister

我试过这个，但仍然无法让它工作。我试过 GROUP BY department_id HAVING count（*）=（SELECT MAX（count（*）） FROM employee GROUP BY department_id） – user5352234

根据您的样本数据，该城市似乎记录在department表的address列中，并且多个部门可以拥有相同的城市。

鉴于此，以及您想“排除达拉斯”的事实，如您所说，我会假设您想过滤掉所有相关的address列为“达拉斯”的部门。

不过，我不知道......

你想在达拉斯，如果他们碰巧与其他部门（或多个）并列为最高的员工排除部门或
如果在确定达到员工数量最多的部门时，您想排除达拉斯的部门。

如果（1）为真：

select * 
    from department_tbl 
where department_id in (select department_id 
          from employee_tbl 
          group by department_id 
         having count(*) = (select max(num_emps) 
              from (select department_id, 
                  count(*) as num_emps 
                from employee_tbl 
                group by department_id))) 
    and address <> 'DALLAS';

如果（2）为真：

select * 
    from department_tbl 
where department_id in (select department_id 
          from employee_tbl 
          group by department_id 
         having count(*) = (select max(num_emps) 
              from (select department_id, 
                  count(*) as num_emps 
                from employee_tbl 
                where address <> 'DALLAS' 
                group by department_id)));

来源

2015-09-19 01:50:25

尝试此。

SELECT d.department_name, 
     d.address 
FROM department d 
     JOIN employee e 
     ON (d.department_id = e.department_id) 
WHERE d.address <> 'DALLAS' 
GROUP BY d.department_name, 
      d.address 
HAVING Count(*) = (SELECT Max(cnt) 
        FROM (SELECT Count(*) CNT 
          FROM employee e 
          WHERE NOT EXISTS (SELECT 'x' 
               FROM department d 
               WHERE d.department_id = 
                e.department_id 
                AND d.address = 'DALLAS') 
          GROUP BY department_id))

来源

2015-09-19 09:13:54

我在Brian DeMilia的回答中遇到的问题是，如果（1）如果达拉斯的雇员人数最多，那么他的查询将不会返回任何结果。我猜你不想那样。（2）尽管他解释了为什么他以这种方式回答，但他并未排除达拉斯的最终结果。你可能也不想要那样。我仍然猜测你想要什么，但是我的查询排除了达拉斯并返回了两个结果。由于这看起来像一个家庭作业问题，我猜测你正在寻找什么。 –

不知道我理解你的问题，但我认为你想这样的：

with emp_count as (
    select d.department_name, 
     d.address, 
     count(*) as num_emps, 
     max(count(*)) over() as max_count 
    from department d 
    join employee e on d.department_id = e.department_id 
    where address <> 'DALLAS' 
    group by d.department_name, d.address 
) 
select * 
from emp_count 
where num_emps = max_count;

这将返回：

DEPARTMENT_NAME | ADDRESS | NUM_EMPS 
----------------+----------+--------- 
SALES   | CHICAGO |  3 
EXECUTIVE  | NEW YORK |  3

SQLFiddle例如：http://sqlfiddle.com/#!4/05db83/1

来源

2015-09-19 10:25:20

select e.department_id, d.department_name, count(e.department_id) 
from employee e, department d 
where e.department_id = d.department_id 
group by e.department_id, d.department_name 
having count(e.department_id)=(select max(count(department_id)) 
           from employee 
           group by department_id);

希望它有帮助

来源

2017-03-23 16:12:25 Moreno

SQL - 选择名称和其员工的最大数量各部门的地址

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