Question

我正在为一个精选案例尝试SQL语句。 'when'有一个转换日期。这是在抛出错误。我错过了什么？

SELECT DISTINCT
    'detail', n.UserName, n.StatusCodeDesc,
    CASE 
       WHEN n.enddate IS NULL AND (n.statuscode = 'L' or n.statuscode = 'P')
         THEN (CONVERT(VARCHAR(10), getdate(), 101) AS [MM/DD/YYYY])
       ELSE (CONVERT(VARCHAR(10), n.EndDate, 101) AS [MM/DD/YYYY])
    END,
    n.TC_OBT_STAT 
FROM  
    tbl_ActNightlyFeed n 
INNER JOIN
    Tbl_ActExistingFeed g ON n.Empid = g.Empid

Answer 1

列别名应该只出现在case表达式的结尾之后，如下所示：

SELECT DISTINCT
  'detail',
  n.UserName,
  n.StatusCodeDesc,
  CASE 
    WHEN n.enddate IS NULL AND (n.statuscode = 'L' OR n.statuscode = 'P')
    THEN CONVERT(VARCHAR(10), getdate(), 101) 
    ELSE CONVERT(VARCHAR(10), n.EndDate, 101) 
  END AS [MM/DD/YYYY],
  n.TC_OBT_STAT 
FROM tbl_ActNightlyFeed  n 
JOIN Tbl_ActExistingFeed g ON n.Empid = g.Empid

Answer 2

您根本没有选择g表。我建议写这个：

SELECT 'detail', n.UserName, n.StatusCodeDesc,
       (CASE WHEN n.enddate IS NULL AND n.statuscode IN ('L', 'P')
             THEN CONVERT(VARCHAR(10), getdate(), 101)
             ELSE CONVERT(VARCHAR(10), n.EndDate, 101) 
        END) AS [MM/DD/YYYY],
       n.TC_OBT_STAT 
FROM tbl_ActNightlyFeed n 
WHERE EXISTS (SELECT 1
              FROM Tbl_ActExistingFeed g 
              WHERE n.Empid = g.Empid 
             );

如果夜间供稿表可能导致重复，您仍需要select distinct。我猜这个表不会有重复。

选择案例转换日期

2 个答案: