查询删除

Question

我在数据库中有一个Employee表，它有两列employee_card和ledger_month。员工可以与多个分类帐月份有关系。现在我想让员工保持最高的分类帐月，其余的将被删除。

Input:
   Employee_card      Ledger_Month

    1                111112
    1                111114
    2                111112
    2                111114


  Output :

   Employee_card      Ledger_Month

    1                111114
    2                111114

我试过像这样的查询

delete from v2titas.EMPLOYEE_COPY_UPGRADED where card 
not in(select card,max(ledger_month) from v2titas.EMPLOYEE_COPY_UPGRADED  group by card)
or 
ledger_month not in (select card,max(ledger_month) from 
v2titas.EMPLOYEE_COPY_UPGRADED group by card)

但它显示了这样的错误＆＃34;太多的价值＆＃34;。我怎么能这样做？

Answer 1

   DELETE FROM v2titas.EMPLOYEE_COPY_UPGRADED et
WHERE EXISTS (
SELECT *
FROM v2titas.EMPLOYEE_COPY_UPGRADED  it
WHERE et.card = it.card
AND et.Ledger_Month < it.Ledger_Month    );

Answer 2

尝试以下查询..

从emp_test中删除ledger_month in（从emp_test e中选择ledger_month，其中（employee_card，ledger_month）不在 （从emp_test e1中选择employee_card，max（ledger_month），其中e.employee_card = e1.employee_card group by employee_card））;

谢谢， 巴拉