Question

我有以下查询来提取属性。属性有多个单元。我不知道如何拉至少一个单位的属性。单位通过拥有相同的“团队”连接到属性。 “团队”是varchar（例如“jkdgsl”）。有什么建议？

SELECT DISTINCT Properties.id, Properties.title, Properties.team
FROM Properties
INNER JOIN Units ON Units.team = Properties.team 
AND Units.rates != '0' 
AND Properties.deleted =  '0000-00-00 00:00:00'
AND Properties.zip_code
IN (
'77808',  '77845'
)
AND Properties.public =  '1'
ORDER BY FIELD( Properties.zip_code,  '77808',  '77845' ) 
LIMIT 0 , 30

Answer 1

我认为你已经按照内部联接的性质这样做了（即选择至少有一个单位的属性）。

Answer 2

我同意@Razvan 如果您还想要计算单位数，请使用：



SELECT DISTINCT Properties.id, Properties.title, Properties.team, COUNT(Units.<em>someOTHERcolumn</em>)
FROM Properties
INNER JOIN Units ON Units.team = Properties.team 
AND Units.rates != '0' 
AND Properties.deleted =  '0000-00-00 00:00:00'
AND Properties.zip_code
IN (
'77808',  '77845'
)
AND Properties.public =  '1'
GROUP BY Properties.id ORDER BY FIELD( Properties.zip_code,  '77808',  '77845' ) 
LIMIT 0 , 30

SELECT DISTINCT Properties.id, Properties.title, Properties.team, COUNT(Units.<em>someOTHERcolumn</em>) FROM Properties INNER JOIN Units ON Units.team = Properties.team AND Units.rates != '0' AND Properties.deleted = '0000-00-00 00:00:00' AND Properties.zip_code IN ( '77808', '77845' ) AND Properties.public = '1' GROUP BY Properties.id ORDER BY FIELD( Properties.zip_code, '77808', '77845' ) LIMIT 0 , 30

Answer 3

如果它只是一个或多个，您可以使用COALESCE。

WHERE COALESCE( Properties.id, Properties.title, Properties.team ) IS NOT NULL

带计数查询的mysql内连接

3 个答案: