您需要使用表别名。您在
from子句中多次提到同一张表。查询是这样的：
SELECt b.BlankTypeCode, b.BlankCode, pa1.Amount, pa1.Type, p1.PurchaseDate, pa2.DatePaidFROM Blank bINNER JOIN Ticket tON b.BlankCode = t.Blank_BlankCodeINNER JOIN MCO_Blank mbON b.BlankCode = mb.Blank_BlankCodeINNER JOIN Purchase p1ON t.PurchaseID = p1.PurchaseIDINNER JOIN Purchase p2ON mb.PurchaseID = p2.PurchaseIDINNER JOIN Payment pa1ON t.PurchaseID = pa1.PurchaseIDINNER JOIN Payment pa2ON mc.PurchaseID = pa2.PurchaseIDWHERe pa1.Status = "Paid";
我不得不猜测别名应该使用哪种付款方式和购买方式。这些在
fromand
where子句中可能不正确。
