select customerId form Sales.Customers as C ------ step 1
where not exists ----- step5
( select * from HR.Employees as E -------step 2
where country = 'USA'
and not exists ------ step 4
( select * from Sales.Orders as O ------ step3
where O.customerId = C.customerId
and O.employeeId = E.emploeeId
));
这个语句的执行顺序是我如上step步骤么?
谢谢。
数据库很久没碰,忘光了
where not exists ----- step5
( select * from HR.Employees as E -------step 2
where country = 'USA'
and not exists ------ step 4
( select * from Sales.Orders as O ------ step3
where O.customerId = C.customerId
and O.employeeId = E.emploeeId
));
这个语句的执行顺序是我如上step步骤么?
谢谢。
数据库很久没碰,忘光了
然后where
最后select