c# - 如何在sql查询中得到正确的结果？

Question

我想查询我的 Membership 表以获得特定成员的结果，但我得到了错误的结果。这是我的查询:

  select MemNo, MemDOB, MemberType, MemShrBal
  From Membership
  Where MemberType = 1 or MemberType = 2 
  and MemDOB > '1973/12/31' 
  and MemShrBal = 250.00

谁能帮我找出原因:除了正确的 member 记录外，我还获得了 MemShrBal 超过 250.0 的那些 member 记录，并且MemDOB 低于“1973”？

Answer 1

你需要一些括号:

select MemNo, MemDOB, MemberType, MemShrBal
  From Membership
  Where (MemberType = 1 or MemberType = 2)
  and MemDOB > '1973/12/31' 
  and MemShrBal = 250.00

and 比 or 绑定(bind)得更紧密，所以没有括号，它是

  MemberType = 1

  or
      MemberType = 2
      and MemDOB > '1973/12/31' 
      and MemShrBal = 250.00