SQL查询未产生结果

Question

我正在尝试解决这个问题： 查找所有精灵的视频，其中创建者是唯一的观看者。基本上找到所有观看者是创作者的视频。

    PreparedStatement pstmt = connection.prepareStatement("Select videoName from videos video natural join accountInformation natural join viewerAccount where " +
    "viewerName = creatorName and video.videoName not in (Select videoName from videos natural join accountInformation natural join viewerAccount v where " +
    "video.creatorName != v.viewerName);");

    ResultSet resultSet = pstmt.executeQuery();

但是，我的查询从未产生结果。 有没有办法可以做到这一点？我觉得我有正确的主意，但我现在就被卡住了。请找到下表：

    String viewerAccount = "create table viewerAccount ("
    + " viewerName CHAR(100),"
    + " accountID integer,"
    + " primary key(viewerName),"
    + " foreign key (accountID) references accounts)";

    connection.createStatement().executeUpdate(viewerAccount);


    String videos = "create table videos "
    + "(link CHAR(50),"
    + " creatorName VARCHAR(100),"
    + " videoName VARCHAR(100),"
    + " duration integer,"
    + " primary key(link))";

    connection.createStatement().executeUpdate(videos);


    String accountInfo = "create table accountInformation ("
    + " accountID integer,"
    + " time integer,"
    + " link CHAR(50),"
    + " primary key(accountID,time,link),"
    + " foreign key (accountID) references accounts,"
    + " foreign key (link) references videos)";

    connection.createStatement().executeUpdate(accountInfo);