如何在使用情况下在什么情况下使用tsql？

Question

以下是一个存储过程的一部分： -

@ID int 
@Col1 int 
@Col2 int 

Select * 
from Table_01 t1 
JOIN table_02 t2 on t1.col = t2.col 
where 
    1 = case when @Col1 = 0 then 1 else (case when t2.Col1 = @Col1 then 1 else 0 end) end 
    AND 1 = case when @Col2 = 0 then 1 else (case when t2.Col2 = @Col2 then 1 else 0 end) end 
    AND 1 = case when @ID = 0 then 1 else (case when t2.ID = @ID then 1 else 0 end) end 

目前

• 如果@ID = 0那么它忽略条件
• 如果@ID有值，那么它基于标准的满意度返回结果

我需要在那里添加另一个条件： -

if @ID = -1那么应该不返回任何结果（堂妹没有匹配） 但它应该像@ID = 0（忽略添加expresssion）

我是清楚了吗？ :(

Answer 1

Select ... 
From Table_01 As t1 
    Join table_02 As t2 
     On t1.col = t2.col 
Where Case 
     When @ID = 0 Then 1 
     When t2.ID = @ID Then 1 
     When @ID = -1 Then 0 
     Else 0 
     End = 1 

如果这最后一个条件应该胜过其他两个，那么你需要改变这个顺序：

Select ... 
From Table_01 As t1 
    Join table_02 As t2 
     On t1.col = t2.col 
Where Case 
     When @ID = -1 Then 0 
     When @ID = 0 Then 1 
     When @ID = t2.ID Then 1 
     Else 0 
     End = 1 

它当然可以进行另一种方式更好的（假设@ID = -1胜过）：

Select ... 
From Table_01 As t1 
    Join table_02 As t2 
     On t1.col = t2.col 
Where @ID != -1 
    And (@ID = 0 Or @ID = t2.ID) 

更新基于OP的编辑

这听起来像你试图做类似如下：

Select ... 
From Table_01 As t1 
    Join table_02 As t2 
     On t1.col = t2.col 
Where @ID != -1 
    And (@Col1 = 0 Or @Col1 = t2.Col1) 
    And (@Col2 = 0 Or @Col2 = t2.Col2) 
    And (@ID = 0 Or @ID = t2.ID) 

Answer 2

我会尝试写它，所以它是清晰的：

WHERE @ID IN (0, t2.ID) AND @ID <> -1 

或

WHERE (@ID = 0 OR t2.ID = @ID) AND @ID <> -1 

如果T2 .ID不能是-1，那么你不需要那部分。

Answer 3

如果我理解正确，您只需要@ID = -1与@ID = 0具有相同的效果。在这种情况下，您的查询可能如下所示：

Select * 
FROM Table_01 t1 
    JOIN table_02 t2 on t1.col = t2.col 
WHERE @Col1 IN (0, t2.Col1) 
    AND @Col2 IN (0, t2.Col2) 
    AND @ID IN (-1, 0, t2.ID)