Question

我想要的是有一个SELECT，它根据表的值和两个变量设置一个名为Current的字段的值，这两个变量被声明为存储过程的输入，其中select如下：

DECLARE @AdminTestId INT = 111
DECLARE @UserTestId INT = null
AdminTestId      UserTestId     Current
111                             1
111                             1
222                             0
333                             0

DECLARE @AdminTestId INT = 111
DECLARE @UserTestId INT = 457
AdminTestId      UserTestId     Current
111              456            0
111              457            1
123                             0

一些帮助和建议将不胜感激。

Answer 1

SELECT
  ...
  CAST(CASE
    WHEN t.AdminTestID = @AdminTestID 
      AND (t.UserTestID = @UserTestID
        OR @UserTestID is NULL AND t.UserTestID is NULL)
    THEN 1
    ELSE 0
  END as bit) as Current
FROM ...

Answer 2

如果 UserTestId 为空或与UserTestId列匹配，您似乎有一些逻辑，其中 Current 只应设置为1。您可以在SQL查询中使用case语句，如下所示：

DECLARE @AdminTestId INT = 111
DECLARE @UserTestId INT = 457

SELECT
   AdminTestId,
   UserTestId
   CASE
     WHEN (@AdminTestId IS NULL AND @UserTestId IS NULL) THEN 0
     WHEN (@AdminTestId = AdminTestId AND @UserTestId = UserTestId) THEN 1
     WHEN (@AdminTestId = AdminTestId AND @UserTestId IS NULL) THEN 1
     WHEN (@AdminTestId IS NULL  AND @UserTestId = UserTestId) THEN 1
ELSE 0
END AS IsCurrent

如何根据参数设置SELECT中字段的值？

2 个答案: