Join 多个相关表上的联接
我有3个表customer(customerid,name),customerbooking(bookingid,customerid),transact(transact,bookingid,typeoftransaction)Join 多个相关表上的联接,join,inner-join,correlation,correlated-subquery,Join,Inner Join,Correlation,Correlated Subquery,我有3个表customer(customerid,name),customerbooking(bookingid,customerid),transact(transact,bookingid,typeoftransaction) 我想获取最大typeoftransact='current'类型的'customer name'的名称。Customer表通过customerid链接到customerbooking,customerbooking通过bookingid链接到transact。使用jo
我想获取最大typeoftransact='current'类型的'customer name'的名称。Customer表通过customerid链接到customerbooking,customerbooking通过bookingid链接到transact。使用join我可以获取单个记录,但无法获取最大值请尝试此操作以满足您的场景
SELECT
C.Name
, Count(BookingID)
FROM Customer C
INNER JOIN customerbooking CB ON CB.CustomerID = C.customerId
INNER JOIN transact T ON T.bookingid = CB.BookingId
WHERE T.Typeoftransaction='current'
GROUP BY C.Name
希望这有帮助换句话说,您想要拥有最“最新”交易记录的客户?