在LINQ中针对SQL Compact 3.5 SP2分组/计数 [英] Group by/count in LINQ against SQL Compact 3.5 SP2

问题描述

您好，我在C＃中使用LINQ-To-Entities并对SQL Compact Server 3.5 SP2运行查询。

我尝试实现的是一个简单的组where子句包含Count（）。

Hello, I am using LINQ-To-Entities in C# and run queries against a SQL Compact Server 3.5 SP2.
What I try to achieve is a simple group by with an additional where clause which includes a Count().

 

var baseIdent="expression";
var found=from o in ObservedElements
  where o.ObservedRoots.BaseIdent==baseIdent
  group o by o.ID into grouped
  where grouped.Count()==1
  select new {key=grouped.Key, val=grouped};
foreach(var res in found){
  //do something here
}

此查询抛出着名的异常"A"此位置不允许参数。确保'@'符号和所有其他参数都在SQL语句中的有效位置。"
$


当我省略where子句或直接输入表达"表达"在查询中（其中o.ObservedRoots.BaseIdent ==" expression"）一切正常.│


有人知道如何解决这个问题吗？解决方法也没关系？在此先感谢，塞巴斯蒂安以

 

This query throws the famous exception "A parameter is not allowed in this location. Ensure that the '@' sign and all other parameters are in a valid location in the SQL statement."

When I either omit the where clause OR directly enter the expression "expression" in the query (where o.ObservedRoots.BaseIdent=="expression") everything just works fine.

Does anybody know how to solve this? Workaround would also be fine? Thanks in advance, Sebastian

 

推荐答案

您好，

此错误是查询处理器错误之一：

http ：//technet.microsoft.com/en-us/library/ms172350.aspx

This error is one of the query processor errors:
http://technet.microsoft.com/en-us/library/ms172350.aspx

目前，您可以直接使用表达式来避免它。如果这是一个紧急问题，请与Microsoft产品支持服务联系：

http://support.microsoft.com/

Currently, you could use the expression directly to avoid it. If it is an urgent issue, please contact Microsoft Product Support Service:
http://support.microsoft.com/

祝你好运

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