由于每张相册有多张照片，您将获得重复。要获得一个，使用
row_number()：
SELECt Album_Name AS Album_Name, a.Album_Date AS Album_Date, a.Page_ID AS PageID, p.Image_ID AS Image_ID, p.Image_Small AS Image_Small FROM Album_Name a left outer JOIN (select p.*, row_number() over (partition by Album_Id order by Image_ID) as seqnum from Album_Photos p ) p ON a.Album_ID = p.Album_ID and seqnum = 1;
