插入使用案例语句

Question

我正在尝试使用带有一个参数的存储过程将数据插入表中。该参数正在寻找俱乐部的名称。我希望SP找到所有属于俱乐部的球员，并将其插入俱乐部。问题是当我运行SP时，它将所有数据从联接中插入表中，而不仅仅是案例语句为真时。

CREATE PROCEDURE SSIS.usp_ClubNameTable 
    -- Add the parameters for the stored procedure here
    @NameOfClub nvarchar(200)
AS
BEGIN
    TRUNCATE TABLE SSIS.ClubNameTable;
    insert into ssis.ClubNameTable ([NameOfClub], [FirstName], [LastName])
        SELECT
            p.FirstName,
            COUNT(p.LastName) as 'Number of Last Names',                
            CASE
                WHEN @NameOfClub = 'Eagle Plate' THEN NameOfClub
                WHEN @NameOfClub = 'Atlanta United FC' THEN NameOfClub
                    ELSE 'Please choose either Eagle Plate or Atlanta United FC'
                end
    FROM [Location].Club as C
            JOIN [Location].ClubDetails as CD on c.ClubID = cd.ClubID
            JOIN [Player].Player as P on CD.PlayerID = P.PlayerID
            GROUP BY c.NameOfClub, p.FirstName, p.LastName
            ORDER BY p.LastName ASC
        declare 
        @RowCount int
            SET @RowCount = (SELECT COUNT(*) FROM Location.Club)
END
GO

Answer 1

在列上使用case statement在记录上不进行任何过滤，它只是在要分配给列的值的条件上。为了过滤记录，您需要在所需条件下使用where子句：

 CREATE PROCEDURE SSIS.usp_ClubNameTable 
    -- Add the parameters for the stored procedure here
    @NameOfClub nvarchar(200)
AS
BEGIN
    TRUNCATE TABLE SSIS.ClubNameTable;
    if(@NameOfClub = 'Eagle Plate' or @NameOfClub = 'Atlanta United FC')
    begin
    insert into ssis.ClubNameTable ([NameOfClub], [FirstName], [LastName])
        SELECT
            p.FirstName,
            COUNT(p.LastName) as 'Number of Last Names',                
            NameOfClub
    FROM [Location].Club as C
            JOIN [Location].ClubDetails as CD on c.ClubID = cd.ClubID
            JOIN [Player].Player as P on CD.PlayerID = P.PlayerID
            Where C.NameOfClub = @NameOfClub
            GROUP BY c.NameOfClub, p.FirstName, p.LastName
            ORDER BY p.LastName ASC
        declare 
        @RowCount int
            SET @RowCount = (SELECT COUNT(*) FROM Location.Club)
    end
    else
    begin
    select 'Please choose either Eagle Plate or Atlanta United FC'
    end
END
GO