Question

我有一个相当大的查询，它的快递部分是让它不起作用我不确定为什么，没有错误出现，但也许我没有看到的东西......

SELECT o.purchaseNo, o.dateCreated, c.Name, m.mouldName, cr.courierName
FROM products AS p
INNER JOIN orderedProducts AS op ON op.productID = p.productID
INNER JOIN orders AS o ON op.orderID = o.orderID
INNER JOIN Couriers AS cr ON cr.couriersID = o.couriersID
INNER JOIN customers AS c ON c.customerID = o.customerID
INNER JOIN Moulds AS m ON m.mouldID = p.mouldID
WHERE c.Name LIKE  '%john%'
OR p.name LIKE  '%john%'
OR c.Name LIKE  '%john%'
OR c.POC1 LIKE  '%john%'
OR c.POC2 LIKE  '%john%'
OR c.Address1 LIKE  '%john%'
OR c.Address2 LIKE  '%john%'
OR c.Suburb LIKE  '%john%'
OR c.State LIKE  '%john%'
OR c.Phone LIKE  '%john%'
OR c.Email LIKE  '%john%'
OR c.ABN LIKE  '%john%'
OR c.Fax LIKE  '%john%'
OR c.CompanyName LIKE  '%john%'
OR o.purchaseNo LIKE  '%john%'
OR o.dateCreated LIKE  '%john%'
OR cr.courierName like '%john%'

Couriers cr是导致问题的因素。如果我将它与对cr的任何引用一起删除它就可以了。否则就不会。

关于可能导致这种情况的任何想法？

我基本上是在创建搜索查询。检查数据库中的许多表。如果你对我如何做得更好有任何建议，那就太好了:)）

Answer 1

我猜你需要在快递员处进行LEFT OUTER JOIN。

SELECT o.purchaseNo, o.dateCreated, c.Name, m.mouldName, cr.courierName
FROM products AS p
INNER JOIN orderedProducts AS op ON op.productID = p.productID
INNER JOIN orders AS o ON op.orderID = o.orderID
INNER JOIN customers AS c ON c.customerID = o.customerID
INNER JOIN Moulds AS m ON m.mouldID = p.mouldID
LEFT OUTER JOIN Couriers AS cr ON cr.couriersID = o.couriersID
WHERE c.Name LIKE  '%john%'
OR p.name LIKE  '%john%'
OR c.Name LIKE  '%john%'
OR c.POC1 LIKE  '%john%'
OR c.POC2 LIKE  '%john%'
OR c.Address1 LIKE  '%john%'
OR c.Address2 LIKE  '%john%'
OR c.Suburb LIKE  '%john%'
OR c.State LIKE  '%john%'
OR c.Phone LIKE  '%john%'
OR c.Email LIKE  '%john%'
OR c.ABN LIKE  '%john%'
OR c.Fax LIKE  '%john%'
OR c.CompanyName LIKE  '%john%'
OR o.purchaseNo LIKE  '%john%'
OR o.dateCreated LIKE  '%john%'
OR cr.courierName like '%john%'

我猜测背后的原因： 如果删除Couriers，则会显示结果集。所以你没有找到cr.couriersID = o.couriersID上的匹配，仍然如你想要的结果集尽管匹配或不匹配你需要LEFT OUTER JOIN。

For more, see Pictorial representation on JOINs.

内部联接查询无法正常工作

1 个答案: