SQL 执行错误 - 无法解析查询文本答案

【问题标题】：SQL execution error - Unable to parse query textSQL 执行错误 - 无法解析查询文本
【发布时间】：2010-10-25 11:33:55
【问题描述】：

我正在尝试创建一份报告，并希望从“联系人”表中提取一些信息。我正在尝试根据一组标准提取与联系人相关的“顾问”以及拥有该顾问的联系人数量。这很好并且有效，但是，我想根据一组不同的标准提取第三列，这也是一个“计数”。这就是我遇到麻烦的地方。

目前我有以下状态“无法解析查询文本”：

SELECT  advisoridName AS Advisor,
  COUNT(*) WHERE (advisorid IS NOT NULL) AND (ContactType = 1) AND (StateCode = 0) AS 'Active Participants',
  COUNT(*) WHERE (advisorid IS NOT NULL) AND (ContactType = 1) AS 'Total Participants'
FROM Contact
GROUP BY  advisoridName, advisorid
ORDER BY  PDA

如果您能引导我朝着正确的方向前进，我们将不胜感激。

提前致谢

【问题讨论】：

标签： sql tsql reporting-services count

【解决方案1】：

COUNT(*) 不是有条件的，至少在 TSQL 中不是。我建议使用SUM(CASE WHEN... - 像这样：

SELECT  advisoridName AS Advisor,
  SUM(CASE WHEN (advisorid IS NOT NULL) AND (ContactType = 1) AND (StateCode = 0) 
           THEN 1
           ELSE 0
      END) AS 'Active Participants',
  SUM(CASE WHEN (advisorid IS NOT NULL) AND (ContactType = 1) 
           THEN 1
           ELSE 0
      END) AS 'Total Participants'
FROM Contact
GROUP BY  advisoridName, advisorid
ORDER BY  PDA

【讨论】：

【解决方案2】：

你可以用 COUNT 做同样的事情，但你不需要 GROUP BY

SELECT COUNT (CASE when advisorid IS NOT NULL AND ContactType = 1 AND StateCode = 0 THEN AdvisorID END ) as ActiveParticipants,
COUNT (CASE when advisorid IS NOT NULL AND ContactType = 1 THEN AdvisorID) as TotalParticipants
FROM Contact
ORDER By PDA

【讨论】：