mysql - SQL 选择所有 Concat 不同的地方

Question

我希望创建一个选择语句，当其中两行的串联不同时，我将在其中选择所有列和行。我的 SQL 语句如下。但是，我不确定如何正确创建该语句，该语句该如何编写？

$query = "SELECT * FROM APPROVED 
  WHERE DISTINCT CONCAT(P_NUMBER,'-',A_NUMBER) AS CNUMBER 
  AND (STATUS = 'ACTIVE' OR STATUS = 'CLOSED' OR STATUS = 'CLOSING' OR STATUS = 'PENDING')"; 

Answer 1

DISTINCT 用于列选择。有几种方法可以做到这一点:

SELECT DISTINCT CONCAT(P_NUMBER,'-',A_NUMBER) AS CNUMBER FROM APPROVED WHERE 
AND (STATUS = 'ACTIVE' OR STATUS = 'CLOSED' OR STATUS = 'CLOSING' OR STATUS =     'PENDING')

这应该做几乎相同的事情

SELECT * FROM APPROVED WHERE 
AND (STATUS = 'ACTIVE' OR STATUS = 'CLOSED' OR STATUS = 'CLOSING' OR STATUS =     'PENDING')
GROUP BY CONCAT(P_NUMBER,'-',A_NUMBER)

第二个不包含结果中的串联，第一个仅包含串联。您需要指定要返回的所有列。