将for的条件
table2移出
WHERe子句并移至您的
JOIN。
SELECt Table1.IDField, Table2.IDFieldFROM Table1LEFT OUTER JOIN Table2 ON Table1.PersonID = Table2.PersonID AND Table2.Category = 'Foo'WHERe Table1.IDField = '12345'
将for的条件
table2移出
WHERe子句并移至您的
JOIN。
SELECt Table1.IDField, Table2.IDFieldFROM Table1LEFT OUTER JOIN Table2 ON Table1.PersonID = Table2.PersonID AND Table2.Category = 'Foo'WHERe Table1.IDField = '12345'
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