Question

我有这样的查询，但它不起作用，带有CASE EXPRESSION的IN关键字出了什么问题？

Select State = case c.addressId
  when in('2552','2478','2526') then 'IN' 
  when in ('9999') then 'OUT'
  else 'UNKNOWN'
  end,
  name, time
from x;

我使用SQL Server 2008，这是错误消息：

关键字附近的语法不正确 '中'。

Answer 1

你的语法错了。它应该是CASE WHEN [COLUMN] in (...)：

Select 
  case when c.addressId in('2552','2478','2526') then 'IN' 
  when c.addressId in ('9999') then 'OUT'
  else 'UNKNOWN'
  end as State,
  name, time
from contact c;

Answer 2

考虑使用连接。

SELECT ISNULL(a.[State], 'UNKNOWN') [State]
    , c.[Name]
    , c.[Time]
FROM [contact] c
LEFT OUTER JOIN
(
    SELECT 2552 AddressId, 'IN' [State]
    UNION ALL SELECT 2478, 'IN'
    UNION ALL SELECT 2526, 'IN'
    UNION ALL SELECT 9999, 'OUT'
) [address] a ON a.AddressId = c.AddressId;

在SQL语句中使用带有Case表达式的关键字[IN]

2 个答案: