插入使用案例聲明

Question

我正在嘗試使用具有一個參數的存儲過程將數據插入表中。 該參數正在尋找俱樂部的名稱。 我希望SP查找屬於俱樂部的所有球員，並將其插入ClubNameTable。 問題是，當我運行SP時，它會將聯接中的所有數據插入表中，而不僅僅是case語句為true時。

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不會對記錄進行任何過濾，它只是對要分配給該列的值應用條件。 為了過濾記錄，您需要使用帶有所需條件的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