Question

我正在尝试计算视图中不同电子邮件地址的数量，但我无法弄清楚语法......这就是我所拥有的：

BEGIN
  SELECT COUNT(*) AS UserCount FROM (
    SELECT DISTINCT EmailAddress 
    FROM viewCohortsAuthorizedByContractor
    WHERE (ListAccess = 1) AND (ContractorId = @id)
  )
END

内部选择工作正常，但如果我尝试添加COUNT，我会收到以下错误：消息156，级别15，状态1，过程rptContractorUsersWithListUserCount，第23行[批处理开始行15] 关键字＆＃39; END＆＃39;附近的语法不正确。

我确定这是一个简单的解决方案，我无法弄明白......

Answer 1

您不需要子查询。试试这个：

SELECT count(DISTINCT EmailAddress) as UserCount
FROM viewCohortsAuthorizedByContractor
WHERE (ListAccess = 1) AND (ContractorId = @id)

Answer 2

BEGIN
  SELECT COUNT(*) AS UserCount FROM (
    SELECT DISTINCT EmailAddress 
    FROM viewCohortsAuthorizedByContractor
    WHERE (ListAccess = 1) AND (ContractorId = @id)
  )A   -----give a name for result set
END

在T-SQL中计算DISTINCT值

2 个答案: