WHERE子句

Question

我有以下表格：

address_components（table）

ADDRESS_ID       STREET_NUMBER            STREET_NAME
-----------------------------------------------------
001              1402                     Motz
002              505                      31st
003              4100                     Stimmel

属性（表格）

ID              ATTRIBUTE_DEFINITION_ID         VALUE
----------------------------------------------------------------
001             Lot                             546
001             SubDiv                          Avondale Spring
002             Lot                             546 
002             SubDiv                          Garden
003             Lot                             131
003             SubDiv                          Avondale Spring

以下SQL语句：

SELECT 
    street_number,street_name
FROM 
    address_components a, attributes attr 
WHERE 
    a.address_id = attr.id 
    AND EXISTS (SELECT 1 FROM attributes 
                WHERE attr.attribute_definition_id = 'Lot'   
                  AND attr.value = '546') 
    AND EXISTS (SELECT 1 FROM attributes 
                WHERE attr.attribute_definition_id = 'SubDiv' 
                  AND attr.value = 'Avondale spring')

我正在尝试选择address_components row＆＃34; 001＆＃34;因为我正在尝试检索两个属性条目都为＆＃34; lot = 546＆＃34;和SubDiv = Avondale Spring＆＃34;。不是两者都必须存在。

查询返回没有匹配项;但是，当我使用单个子查询进行查询时（消除2个子查询中的1个），将为该单个查询返回请求的行。

Answer 1

查询背后的想法很好。但是from子句中不需要两个表;你想要相关子查询：

SELECT a.street_number, a.street_name
FROM address_components a
WHERE EXISTS (SELECT 1
              FROM attributes attr
              WHERE a.address_id = attr.id AND attr.attribute_definition_id = 'Lot' AND  attr.value = '546'
             ) AND
      EXISTS (SELECT 1
              FROM attributes attr
              WHERE a.address_id = attr.id AND attr.attribute_definition_id = 'SubDiv' AND attr.value = 'Avondale spring'
             );

Answer 2

SELECT top 1 a.street_number,a.street_name from address_components a
              inner join attributes k on  a.ADDRESS_ID=k.ID
              WHERE k.ATTRIBUTE_DEFINITION_ID in('Lot','SubDiv')  AND
              k.value in('546','Avondale Spring')