内部多次连接同一张表 [英] Inner Joining the same table multiple times
本文介绍了内部多次连接同一张表的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
所以我收到此错误:#1066-不是唯一的表/别名:'购买'
So I have received this error: #1066 - Not unique table/alias: 'Purchase'
我正在尝试执行以下操作:
I am trying to do the following:
SELECT Blank.BlankTypeCode
,Blank.BlankCode
,Payment.Amount
,Payment.Type
,Purchase.PurchaseDate
,Payment.DatePaid
FROM Blank
INNER JOIN Ticket
ON Blank.BlankCode = Ticket.Blank_BlankCode
INNER JOIN MCO_Blank
ON Blank.BlankCode = MCO_Blank.Blank_BlankCode
INNER JOIN Purchase
ON Ticket.PurchaseID = Purchase.PurchaseID
INNER JOIN Purchase
ON MCO_Blank.PurchaseID = Purchase.PurchaseID
INNER JOIN Payment
ON Ticket.PurchaseID = Payment.PurchaseID
INNER JOIN Payment
ON MCO_Blank.PurchaseID = Payment.PurchaseID
WHERE Payment.Status = "Paid";
空白表包含:
BlankCode,
IssueDate,
Status,
UserID,
BlankTypeCode
付款表包含:
Type,
Amount,
Status,
DueDate,
PurchaseID,
CurrencyRateDate
购买表包括:
PurchaseID,
CustomerID,
PurchaseDate,
TotalFare,
TaxAmount,
CurrencyType,
Purchasecol
机票表包括:
Price,
PurchaseID,
Blank_BlankCode,
Blank_BlankTypeCode,
TicketType,
Airline_Name
MCO_Blank表包含:
MCO_Blank Table consists of:
Service,
Cost,
Description,
Purchase_PurchaseID,
Blank_BlankCode,
Blank_BlankTypeCode
我不确定如何进行这项工作.
I am unsure of how I can make this work.
推荐答案
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:
You need to use table aliases. You have mentioned the same table more than once in the from
clause. The query is something like this:
SELECT b.BlankTypeCode, b.BlankCode, pa1.Amount, pa1.Type, p1.PurchaseDate, pa2.DatePaid
FROM Blank b
INNER JOIN Ticket t
ON b.BlankCode = t.Blank_BlankCode
INNER JOIN MCO_Blank mb
ON b.BlankCode = mb.Blank_BlankCode
INNER JOIN Purchase p1
ON t.PurchaseID = p1.PurchaseID
INNER JOIN Purchase p2
ON mb.PurchaseID = p2.PurchaseID
INNER JOIN Payment pa1
ON t.PurchaseID = pa1.PurchaseID
INNER JOIN Payment pa2
ON mc.PurchaseID = pa2.PurchaseID
WHERE pa1.Status = "Paid";
我不得不猜测要为别名使用的付款方式和购买方式.在from
和where
子句中,这些可能不正确.
I had to make a guess at which payment and purchase is intended for the aliases. These may not be correct in the from
and where
clauses.
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