[英]Use of AND instead of JOIN with PHP based MySQL query
据我所知,AND不能用于指定两个不同的表,但是有另一种方法可以简单地在两个不同的表中查询完全相同的列名吗?
目前我有一个PHP变量:
define('TB_RESI', 'RESI');
和下面的查询一样。 我还需要使用相同的列查询名为RESI的表...实现此目的的最佳方法是什么?
当前查询:
$sql = 'SELECT PictureCount AS PIC_COUNT, DATE(PictureModifiedDateTime) AS FILE_DATE, ListingRid AS HOME_ID
FROM ' . TB_RESI .
' WHERE (COUNTY = "Lee") AND (
ListingOfficeMLSID = "PREFP" OR
ListingOfficeMLSID = "PREFP2" OR
ListingOfficeMLSID = "PREFP3" OR
ListingOfficeMLSID = "PREFP4" OR
ListingOfficeMLSID = "PREFP6"
)
AND (PictureCount >= 4)
ORDER BY EntryDate DESC';
使用UNION组合两个表
$sql = 'SELECT PictureCount AS PIC_COUNT, DATE(PictureModifiedDateTime) AS FILE_DATE, ListingRid AS HOME_ID
FROM (SELECT * FROM ' . TB_RESI . ' UNION SELECT * FROM ' . RESI . ') AS ALL' .
' WHERE (COUNTY = "Lee") AND (
ListingOfficeMLSID = "PREFP" OR
ListingOfficeMLSID = "PREFP2" OR
ListingOfficeMLSID = "PREFP3" OR
ListingOfficeMLSID = "PREFP4" OR
ListingOfficeMLSID = "PREFP6"
)
AND (PictureCount >= 4)
ORDER BY EntryDate DESC';
如果两个表之间包含链接,请使用INNER JOIN拉入第二个图片表。
SELECT tbla.x, tbla.y, tblb.f
FROM tbla
INNER JOIN tblb ON tblb.id = tbla.tblbid
WHERE tbla.x = 'test' AND tblb.f > 4;
我试图让这个例子尽可能简单。
好吧,看起来你应该从你所做的评论和回复中走下UNION路线。
SELECT PictureCount AS PIC_COUNT, DATE(PictureModifiedDateTime) AS FILE_DATE, ListingRid AS HOME_ID
FROM (SELECT * FROM ' . TB_RESI . '
WHERE (COUNTY = "Lee") AND (
ListingOfficeMLSID = "PREFP" OR
ListingOfficeMLSID = "PREFP2" OR
ListingOfficeMLSID = "PREFP3" OR
ListingOfficeMLSID = "PREFP4" OR
ListingOfficeMLSID = "PREFP6"
)
AND (PictureCount >= 4)
ORDER BY EntryDate DESC
UNION
SELECT PictureCount AS PIC_COUNT, DATE(PictureModifiedDateTime) AS FILE_DATE, ListingRid AS HOME_ID
FROM (SELECT * FROM ' . TB_RESI2 . '
WHERE (COUNTY = "Lee") AND (
ListingOfficeMLSID = "PREFP" OR
ListingOfficeMLSID = "PREFP2" OR
ListingOfficeMLSID = "PREFP3" OR
ListingOfficeMLSID = "PREFP4" OR
ListingOfficeMLSID = "PREFP6"
)
AND (PictureCount >= 4)
ORDER BY EntryDate DESC
其中TB_RESI是第一个表的名称,TB_RESI2是第二个表名
如果由于某种原因不想进行JOIN,可以使用多种SQL(例如MySQL)来命名表,并在WHERE子句中使用该名称:
FROM ' . TB_RESI . ' as TBR, ' . TC_RESI . ' as TCR ' .
...
WHERE TBR.field1 = TCR.field2
当然,你应该看看使用JOIN是否是一个更好的解决方案。
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