Question

我有一个关于在sql中编写查询的问题（继续上一个问题：subtract values of two rows and inserting it into a new column (not subsequent rows)）：

我想写一个查询来计算用户在当前时间之前赢得比赛的次数，获胜的条件是place = 1;我希望结果出现在新列（win-frequency）中，并且[win-frequency]的值会在新的获胜发生时发生变化。在下图中，我手动计算了win-frequency。

http://www.8pic.ir/images/54691148512772358477.jpg

我写了以下查询，但是我收到了错误：

SELECT [user-name], 
   submissions,
   [date],
   place,
   recency,
   [win-recency],
   COUNT( SELECT [date] FROM [top-design1]] td1
          WHERE td1.[user-name] = [top-design1].[user-name]
          AND  place=1
          AND [date]< [top-design1].[date]
          ORDER BY [date] DESC) as win-frequency
        )
FROM [top-design1]

这是sql小提琴： http://sqlfiddle.com/#!3/0ec5f

Answer 1

您必须修复方括号)和[，从相关子查询中删除ORDER BY，然后转义列名[win-frequency]。它应该是这样的：

SELECT [user-name], 
   submissions,
   [date],
   place,
   recency,
   [win-recency],
   (SELECT COUNT([date])
    FROM [top-design1] td1
    WHERE td1.[user-name] = [top-design1].[user-name]
      AND  place = 1
      AND [date] < [top-design1].[date]
    ) as [win-frequency]
FROM [top-design1];

Updated SQL Fiddle Demo.

满足条件的COUNT行（在具有特定条件的行中重置）

1 个答案: