Question

我想创建一个返回所有Country行的SP，除非提供CountryID作为参数。这是我想象它可能会起作用的方式，但它不喜欢它。

ALTER PROCEDURE [dbo].[usp_return_countries]
    @CountryID AS INT = 0
AS
BEGIN
        SELECT *
        FROM Countries
        WHERE Active = 1

        IF @CountryID > 0 BEGIN
            AND @CountryID = CountryID
        END

END

谢谢

P.S。我认为可能有一种更好的方法，而不是简单地根据上述条件重复整个SELECT语句。

Answer 1

试试这个，它很优雅：）

 ALTER PROCEDURE [dbo].[usp_return_countries]
   @CountryID AS INT = 0
 AS
 BEGIN

    SELECT *
    FROM Countries
    WHERE Active = 1
    AND (@CountryID = 0 OR @CountryID = CountryID)

 END

Answer 2

很容易包含在单个WHERE子句中：

SELECT * 
FROM Countries 
WHERE Active = 1 AND (@CountryID = 0 OR CountryID = @CountryID)

Answer 3

这样做：

ALTER PROCEDURE [dbo].[usp_return_countries]
    @CountryID AS INT = 0 AS BEGIN

        IF @CountryID > 0 BEGIN
            SELECT *
            FROM Countries
            WHERE Active = 1
            AND @CountryID = CountryID
        END
        ELSE BEGIN
            SELECT *
            FROM Countries
            WHERE Active = 1
        END

END

Answer 4

这样的东西？

SELECT *
        FROM Countries
        WHERE Active = 1
AND
    (CountryID = @CountryID AND @CountryID <> 0) or (@CountryID = 0)

条件WHERE语句SQL Server

4 个答案: