MYSQL OR与AND同时出现的用法

表中数据

MySQL中or和and的用法

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1 2	SELECT * from student WHERE id = 1 or id = 2 AND age = 20; -- 查询结果是id = 2且age = 20或者id=1

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1 2	SELECT * from student WHERE (id = 1 or id = 2 ) AND age = 20; -- 查询结果是 id=1或id=2 且age = 20

问题记录：要求查出 INVOICE_TITLE like ‘12%’或者CLIENT_NAME LIKE ‘%12%’的数据，结果前台一直报请求超时，发现数据多了将近20倍，SQL如下：

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SELECT     * FROM     ewin_should_receive sr,     ewin_client_snap cs WHERE     sr.client_snap_id = cs.id AND sr.b_enable = '1' AND cs.INVOICE_TITLE LIKE '%12%' OR cs.CLIENT_NAME LIKE '%12%'

正确SQL：

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SELECT     * FROM     ewin_should_receive sr,     ewin_client_snap cs WHERE     sr.client_snap_id = cs.id AND sr.b_enable = '1' AND (     cs.INVOICE_TITLE LIKE '%12%'     OR cs.CLIENT_NAME LIKE '%12%' )

　

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