此SQL查询
(SELECT * FROM OperatorRoster as roster
INNER JOIN ( SELECT *, count(*) as activeSlots FROM Connectors
group by (operator)) as connectors
ON connectors.operator = roster.operator)
工作正常并返回我需要的所有值,但我需要在新的查询中使用restult
但如果我尝试使用它:
SELECT * FROM (SELECT * FROM OperatorRoster as roster
INNER JOIN ( SELECT *, count(*) as activeSlots FROM Connectors
group by (operator)) as connectors
ON connectors.operator = roster.operator) as q
它什么也不吐。如何查询此子查询?
您缺少主联接的ON子句。
on q.___= Operators.___
由于您使用的是内部联接,您确定在connectors.operator=roster.operator
如果没有符合该要求的行,则查询不应返回任何行
事实证明,由于我对运算符进行了联接,但选择了所有字段,
(SELECT * FROM OperatorRoster as roster
INNER JOIN ( SELECT *, count(*) as activeSlots FROM Connectors
group by operator) as connectors
ON connectors.operator = roster.operator)
它返回两个名称相同的字段"connectors.operator"one_answers"花名册.operators",由于最后一个选择不能继承独家新闻,因此它发生冲突。不知道为什么它没有返回错误,但我只选择了一个运算符字段就修复了它。