数据结构和示例:id name2 Lisa Miller
eid name1 PHPSELECT * FROM Employees LEFT JOIN Skills ON (Employees.id = Skills.eid) WHERE Skills.name ="SQL" OR Skills.name = "PHP" GROUP BY Employees.id
我想写一个SQL来统计我过去六个月的销售额,就像下面的代码一样。 MONTH (pc.createTime) AS MONTH,FROMRIGHT JOIN partscontract pc ON pl.partsContractID = pc.partsContractIDAND pc.createTime BETWEEN '2013/11/01 00:00:00'
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