sql - 列出每个部门的前十名员工

Question

如何按采购总额顺序列出每个部门的前十名员工以及每个部门员工应按采购总额排序的顺序？

这些是表格：

CREATE TABLE EMP (
    EMPNO NUMBER(4),
    ENAME VARCHAR2(20),
    POSITION VARCHAR2(20),
    DEPTNO NUMBER(2)
);

CREATE TABLE DEPT (
    DEPTNO NUMBER(2),
    DNAME VARCHAR2(20)
);

CREATE TABLE CLIENT (
    CLIENTNO NUMBER(5),
    CNAME VARCHAR2(20),
    PHONE VARCHAR2(10)
);

CREATE TABLE PURCHASE (
    PURCHASENO  NUMBER(5),
    RECEIPTNO   NUMBER(6),
    SERVICETYPE VARCHAR2(25),
    PAYMENTTYPE VARCHAR2(10),
    GST     VARCHAR2(3),
    AMOUNT      NUMBER(4),
    SERVEDBY    NUMBER(4),
    CLIENTNO    NUMBER(5)
);

尝试编辑：

SELECT DISTINCT *
FROM (SELECT E.ENAME, D.DEPTNO, COUNT(P.PURCHASENO) AS TOTALAMOUNT,
             AVG(P.AMOUNT)AS AVGAMOUNT, MAX(P.AMOUNT)AS HIGHESTAMOUNT,
             SUM(P.AMOUNT)AS TOTALAMOUNTPURCHASE,
             DENSE_RANK() OVER(PARTITION BY DEPTNO ORDER BY AMOUNT DESC)RANK
      FROM EMP E, DEPT D, PURCHASE P
     )
WHERE RANK<=10

Answer 1

这是解决问题的一种方法：

 select *
 from (select s.deptno, empno,
              row_number() over (partition by s.deptno order by totamount desc) as seqnum
       from (select servedby, sum(amount) as totamount
             from purchase p
             group by servedby
            ) ps join
            emp e
            on ps.servedby = e.empno
       group by deptno, empno
      ) t
 where seqnum <= 10;

您的原始查询缺少表和中间聚合级别之间的连接。