Question

我希望运行一个查询并从中获得结果。但是，MSSQL抱怨GROUP关键字附近出现语法错误。我希望能做到以下几点。

  SELECT COUNT(*) AS cnt,Field_2
    FROM (SELECT DISTINCT Field_1, Field_2 
            FROM Table_1)
GROUP BY Field_2 
  HAVING COUNT(*) > 1

相反，我必须使用查询

创建一个View_1视图

SELECT DISTINCT Field_1, Field_2 
  FROM Table_1

然后做一个

  SELECT COUNT(*) AS cnt, Field_2
    FROM View_1
GROUP BY Field_2 
  HAVING COUNT(*) > 1

问题是为什么，在我看来它基本上是相同的SQL。

注意：已更改字段，表格和视图名称以保护无辜者。 ; - ）

Answer 1

SQL Server要求您为派生表/内联视图指定表别名：

  SELECT COUNT(*) AS cnt, 
         x.Field_2
    FROM (SELECT DISTINCT Field_1, Field_2 
            FROM Table_1) AS x
GROUP BY x.Field_2 
  HAVING COUNT(*) > 1

Answer 2

OMG小马的回答是100％正确的。

我认为这会显示相同的结果，但我现在无法测试：

SELECT COUNT(DISTINCT Field_1) AS cnt
     , Field_2
FROM Table_1
GROUP BY Field_2 
HAVING COUNT(DISTINCT Field_1) > 1

子选择失败，但视图有效

2 个答案: