Question

对于学校项目，我们需要制作一个Web应用程序。其中一个功能应该是您可以导入.csv文件，并且所有行都应该插入到右表中，除非（在这种情况下）歌曲或艺术家已经存在。 .csv文件由2000行组成，应始终将其插入到不同的表中。代码运行，但实际只插入了137行。这是我的代码：

BEGIN
SET NOCOUNT ON;

IF EXISTS(SELECT naam FROM Artiest WHERE naam = @artiest)
PRINT NULL;
ELSE
INSERT INTO Artiest(naam) VALUES (@artiest);
END
BEGIN
SET NOCOUNT ON;

IF EXISTS(SELECT titel FROM Song WHERE titel = @titel AND artiestid = (SELECT artiestid FROM Artiest WHERE naam = @artiest))
PRINT NULL;
ELSE
INSERT INTO Song(artiestid, titel, jaar) VALUES ((SELECT TOP(1) artiestid FROM Artiest WHERE naam = @artiest), @titel, @jaar);
END
BEGIN
SET NOCOUNT ON;

IF EXISTS (SELECT TOP(1) songid FROM Lijst WHERE songid = (SELECT TOP(1) songid FROM Song WHERE titel = @titel AND artiestid = (SELECT artiestid FROM Artiest WHERE naam = @artiest)))
AND EXISTS (SELECT TOP(1) top2000jaar FROM Lijst WHERE top2000jaar = @top2000jaar)
PRINT null;
ELSE
INSERT INTO Lijst (songid, top2000jaar, positie, uitzendDatum, van, tot) VALUES ((SELECT TOP(1) songid FROM Song WHERE titel = @titel AND artiestid = (SELECT artiestid FROM Artiest WHERE naam = @artiest)), @top2000jaar, @positie, @eindzenddatum, @van, @tot);
END

希望有人可以帮助我解决这个问题，因为在谈到SQL时我是个新手

Answer 1

我已经简化了sql以使其更具可读性，

BEGIN
    SET NOCOUNT ON;

    DECLARE @artiestID INT,
            @SongID INT

    SELECT @artiestID = artiestid FROM Artiest WHERE naam = @artiest

    IF @artiestID IS NULL
    BEGIN
        INSERT INTO Artiest(naam) VALUES (@artiest);
        SELECT @artiestID = @@IDENTITY
    END

    SELECT @SongID = songid FROM Song WHERE titel = @titel AND artiestid = @artiestID

    IF @SongID IS NULL
    BEGIN
        INSERT INTO Song(artiestid, titel, jaar) VALUES (@artiestID, @titel, @jaar);
        SELECT @SongID = @@IDENTITY
    END

    IF NOT EXISTS (SELECT 1 FROM Lijst WHERE songid = @SongID) OR NOT EXISTS (SELECT 1 top2000jaar FROM Lijst WHERE top2000jaar = @top2000jaar)
        INSERT INTO Lijst (songid, top2000jaar, positie, uitzendDatum, van, tot) VALUES (@SongID, @top2000jaar, @positie, @eindzenddatum, @van, @tot);
END

验证您的数据以确定目标表记录数量较少的原因。

存储过程不插入所有行

1 个答案: