Question

使用的技术：MySQL 5.1

我在下面有一个MySQL查询：

SELECT 
  property.propertyId,
  categoryRelationships.categoryId
FROM
  property
LEFT OUTER JOIN categoryRelationships ON (property.propertyId = categoryRelationships.propertyId)
WHERE
 categoryRelationships.categoryId IN (11,12)

返回如下结果：

propertyId    categoryId
972           11
1071          11
1622          12
1622          11

但是，我想要做的只是返回propertyId，其中包含类别11和12（在1622以上的情况下）

我试过了

SELECT 
  property.propertyId,
  categoryRelationships.categoryId
FROM
  property
LEFT OUTER JOIN categoryRelationships ON (property.propertyId = categoryRelationships.propertyId)
WHERE
  categoryRelationships.categoryId = 11
  AND categoryRelationships.categoryId = 12

和

SELECT 
  property.propertyId,
  categoryRelationships.categoryId
FROM
  property
LEFT OUTER JOIN categoryRelationships ON (property.propertyId = categoryRelationships.propertyId)
WHERE
  categoryRelationships.categoryId IN (11)
  AND categoryRelationships.categoryId IN (12)

然而，这没有结果，这让我有点疯狂如何做到这一点。

这两个表的一个简单示例是（我从属性表中返回了大量的信息）：

categoryRelationships

categoryRelationshipsId     categoryId      propertyId
2                           9               2136
3                           2               2136
4                           11              1622
5                           12              1622


property

propertyId                  propertyAddress
1622                        1 Anystreet
2136                        156 Stack Road

Answer 1

在我看来，这是最明确，最直接的解决方案：

SELECT p.propertyaddress, t1.pid, t1.cid 
  FROM categoryRelationships t1
       LEFT JOIN property p ON p.property_id = t1.property_id
 WHERE EXISTS (
           SELECT 1 
             FROM categoryRelationships t2 
            WHERE t2.pid = t1.pid 
              AND t2.cid = 11) 
   AND EXISTS (
           SELECT 1 
             FROM categoryRelationships t3 
            WHERE t3.pid = t1.pid 
              AND t3.cid = 12);

由于有时候MySQL不太擅长处理子查询，你可以选择这样做：

SELECT p.propertyaddress, t1.pid, t1.cid 
  FROM categoryRelationships t1 
       LEFT JOIN property p ON p.property_id = t1.property_id
       JOIN categoryRelationships t2 ON t2.pid = t1.pid 
   AND t2.cid = 11 
       JOIN categoryRelationships t3 ON t2.pid = t3.pid 
   AND t3.cid = 12;

使用AND从MySQL中的链接表中选择多个值

1 个答案: