If (select statement 1) returns 0 rows THEN (select statement 2) else (select statement 3)
所以sql从语句2或3中返回结果我已经寻找一种方法来做到这一点,但是迄今为止我发现的没有什么似乎恰恰满足了要求.
IF EXISTS (SELECT field FROM table) BEGIN SELECT field FROM table2 END ELSE BEGIN SELECT field FROM table3 END
