sql - 在 WHERE 语句中使用 IS NULL

Question

 [dbo].[StoreProc1]
 (
 @Name varchar(10) = NULL,
 @Age int
 )

 SELECT * FROM TABLE WHERE Name = @Name and Age = @Age

但是，由于@Name = NULL不正确，存储过程不知道输入是否Name为 Null 或 Not to doName IS NULL或Name = '<value>'

什么是快速解决这个问题？

我想我可以做这样的事情，但没有更简单的方法吗？

IF @Name IS NULL 
BEGIN 
  SELECT * FROM TABLE WHERE NAME IS NULL AND AGE=@AGE
END
ELSE
BEGIN
  SELECT * FROM TABLE WHERE NAME=@NAME AND AGE=@AGE
END

Answer 1

[dbo].[StoreProc1]
 (
 @Name varchar(10) = NULL,
 @Age int
 )

 SELECT * FROM TABLE WHERE (Name = @Name OR COALESCE(Name, @Name) IS NULL) and Age = @Age

Answer 2

改为Name = @Name：

( Name = @Name OR Name IS NULL AND @Name IS NULL )

Answer 3

假设您想在 name = @Name 或它们都为 null 时获得结果，那么我将采用以下方法。

[dbo].[StoreProc1]
(
 @Name varchar(10) = NULL,
 @Age int
)

 SELECT * 
   FROM TABLE 
  WHERE (Name = @Name 
         OR ( Name IS NULL AND @Name IS NULL) )
    AND Age = @Age

希望这可以帮助。

Answer 4

SELECT * FROM TABLE WHERE ISNULL(NAME,'')=ISNULL(@NAME,'') AND AGE=@AGE