Visual Studio 遇到的 SQL 语法错误答案

【问题标题】：SQL Syntax errors encountered visual studioVisual Studio 遇到的 SQL 语法错误
【发布时间】：2016-10-06 12:21:44
【问题描述】：

我收到此错误：

SELECT 子句中的错误：“=”附近的表达式。缺少 FROM 子句。 SELECT 子句中的错误：“，”附近的表达式。无法解析查询文本。

 SELECT Sum(subhearingsched.conclusion = 'Conciliated'
       AND cases.nature_of_case = 'Criminal') AS criminalconciliated,
   Sum(subhearingsched.conclusion = 'Repudiated'
       AND cases.nature_of_case = 'Criminal') AS criminalrepudiated,
   Sum(subhearingsched.conclusion = 'Arbitrated'
       AND cases.nature_of_case = 'Criminal') AS criminalarbitrated,
   Sum(subhearingsched.conclusion = 'Certified'
       AND cases.nature_of_case = 'Criminal') AS criminalcertified,
   Sum(subhearingsched.conclusion = 'Dismissed'
       AND cases.nature_of_case = 'Criminal') AS criminaldismissed,
   Sum(subhearingsched.conclusion = 'Forwarded'
       AND cases.nature_of_case = 'Criminal') AS criminalforwarded,
   Sum(subhearingsched.conclusion = 'Mediated'
       AND cases.nature_of_case = 'Criminal') AS criminalmediated,
   Sum(subhearingsched.conclusion = 'Conciliated'
       AND cases.nature_of_case = 'Civil')    AS civilconciliated,
   Sum(subhearingsched.conclusion = 'Repudiated'
       AND cases.nature_of_case = 'Civil')    AS civilrepudiated,
   Sum(subhearingsched.conclusion = 'Arbitrated'
       AND cases.nature_of_case = 'Civil')    AS civilarbitrated,
   Sum(subhearingsched.conclusion = 'Certified'
       AND cases.nature_of_case = 'Civil')    AS civilcertified,
   Sum(subhearingsched.conclusion = 'Dismissed'
       AND cases.nature_of_case = 'Civil')    AS civilldismissed,
   Sum(subhearingsched.conclusion = 'Forwarded'
       AND cases.nature_of_case = 'Civil')    AS civilforwarded,
   Sum(subhearingsched.conclusion = 'Mediated'
       AND cases.nature_of_case = 'Civil')    AS civilmediated,
   Sum(subhearingsched.conclusion = 'Conciliated'
       AND cases.nature_of_case = 'Others')   AS othersconciliated,
   Sum(subhearingsched.conclusion = 'Repudiated'
       AND cases.nature_of_case = 'Others')   AS othersrepudiated,
   Sum(subhearingsched.conclusion = 'Arbitrated'
       AND cases.nature_of_case = 'Others')   AS othersarbitrated,
   Sum(subhearingsched.conclusion = 'Certified'
       AND cases.nature_of_case = 'Others')   AS otherscertified,
   Sum(subhearingsched.conclusion = 'Dismissed'
       AND cases.nature_of_case = 'Others')   AS othersdismissed,
   Sum(subhearingsched.conclusion = 'Forwarded'
       AND cases.nature_of_case = 'Others')   AS othersforwarded,
   Sum(subhearingsched.conclusion = 'Mediated'
       AND cases.nature_of_case = 'Others')   AS othersmediated
  FROM   subhearingsched
   JOIN cases
     ON ( subhearingsched.caseno = cases.caseno )

这是我的查询，当我在 Visual Studio 查询生成器中运行它时，它显示解析错误，但它在 mysql 工作台中运行良好，这也发生在我的其他查询中，在 mysql 工作台中运行良好但在 Visual Studio 中运行良好.

【问题讨论】：

请在问题中包含错误消息的文本：错误图像不够。
所有subhearingsched.conclusion = 和cases.nature_of_case = 都应该在WHERE 子句中
SELECT 子句中的错误：'=' 附近的表达式。缺少 FROM 子句。 SELECT 子句中的错误：“，”附近的表达式。无法解析查询文本。这是每次我尝试构建查询时出现的错误
i 但我需要指定它，因为不同的列有不同的条件，有没有其他选择？
你想做什么？

标签： c# mysql visual-studio mysql-workbench

【解决方案1】：

不确定您使用的语法是否是 MySQL 方言（因此适用于 MySQL 工作台），但您最好使用标准 SQL，在“SUM”中使用“CASE”，如下所示：

SELECT Sum(CASE WHEN subhearingsched.conclusion = 'Conciliated'
       AND cases.nature_of_case = 'Criminal' THEN 1 ELSE 0 END) AS criminalconciliated
  FROM   subhearingsched
   JOIN cases
     ON ( subhearingsched.caseno = cases.caseno )

【讨论】：

我以前试过这个，但它也不起作用。它显示错误Error in SELECT clause: expression near 'END'. Error in SELECT clause: expression near 'FROM'. Missing FROM clause. Unable to parse query text.
那么您的查询中可能有错字。我建议您逐步分析它：首先从 subhearingsched 中选择 *，然后包含连接，然后包含不带 case 语句的总和，然后添加一个不涉及实际列的简单 case 语句，然后添加 1 列，依此类推on.... 你应该带着你收到的第一个错误回到这里。