Question

输入：

ITEM_NO | ORDER_NO | NAME
-------------------------
  123   |   100    | JOE
  123   |   101    | BOB
  123   |   101    | BOB
  124   |   101    | BOB
  456   |   102    | BOB

所需的输出：

ITEM_NO | ORDER_NO | NAME
-------------------------
  123   |   100    | JOE
  123   |   101    | BOB
  124   |   101    | BOB
  456   |   102    | BOB

基本上，我需要为每个唯一的ORDER_NO选择所有具有唯一ITEM_NO的行。

Answer 1

尝试DISTINCT选择

SELECT DISTINCT ITEM_NO, ORDER_NO, NAME
FROM <TABLE_NAME>

OR

SELECT I.ITEM_NO, I.ORDER_NO, I.NAME 
FROM (SELECT DISTINCT ITEM_NO, ORDER_NO FROM <TABLE_NAME>) AS X
JOIN <TABLE_NAME> I ON I.ITEM_NO = X.ITEM_NO AND I.ORDER_NO = x.ORDER_NO

为另一列的每个唯一值选择具有一个列的唯一值的行

1 个答案: