SQL - 選擇名稱和其員工的最大數量各部門的地址

-1

部門

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

員工

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

我需要顯示除達拉斯外的名稱和地址，擁有最多的員工人數。

我寫了這個：

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

但我只得到一個行

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

我在做什麼錯？

來源

2015-09-18 user5352234

首先，爲什麼你不能獲得單個記錄？你在期待什麼？其次，你爲什麼要做'MAX（department_id）'？你認爲那是什麼？ – sstan

所有你將會得到的是一行，因爲你說的部門ID匹配最大部門ID。所以，最高價值的部門ID。您需要使用「有數」的組。 – CargoMeister

我試過這個，但仍然無法讓它工作。我試過 GROUP BY department_id HAVING count（*）=（SELECT MAX（count（*）） FROM employee GROUP BY department_id） – user5352234

根據您的樣本數據，該城市似乎記錄在department表的address列中，並且多個部門可以擁有相同的城市。

鑑於此，以及您想「排除達拉斯」的事實，如您所說，我會假設您想過濾掉所有相關的address列爲「達拉斯」的部門。

不過，我不知道......

你想在達拉斯，如果他們碰巧與其他部門（或多個）並列爲最高的員工排除部門或
如果在確定達到員工數量最多的部門時，您想排除達拉斯的部門。

如果（1）爲真：

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）爲真：

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)));

來源

2015-09-19 01:50:25

嘗試此。

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))

來源

2015-09-19 09:13:54

我在Brian DeMilia的回答中遇到的問題是，如果（1）如果達拉斯的僱員人數最多，那麼他的查詢將不會返回任何結果。我猜你不想那樣。（2）儘管他解釋了爲什麼他以這種方式回答，但他並未排除達拉斯的最終結果。你可能也不想要那樣。我仍然猜測你想要什麼，但是我的查詢排除了達拉斯並返回了兩個結果。由於這看起來像一個家庭作業問題，我猜測你正在尋找什麼。 –

不知道我理解你的問題，但我認爲你想這樣的：

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;

這將返回：

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

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

來源

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);

希望它有幫助

來源

2017-03-23 16:12:25 Moreno

SQL - 選擇名稱和其員工的最大數量各部門的地址

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