在asp.net中使用C#通过Linq插入数据库之前，如何检查Unique [英] How to check Unique before insert in database through linq with C# in asp.net

问题描述

我正在使用sqlcommand class write的帮助通过c#编码进行独特查找:

I was using for chek unique through c# coding with the help of sqlcommand class write :

select count(*) as v_count from  dbo.BookTopic where TopicId <>1 and Topic=''abc''

很好...

但我想用linq编写此编码...请帮助我...

that is working fine...

But i want to write this coding in linq ...please help me...




Thank''s in Advance.

推荐答案

我假设您有一个名为BookTopic的集合类.然后，这就是LINQ中SQL查询的样子.

I am assuming that you have a collection class called BookTopic. Then here is what the SQL query will look like in LINQ.

int count = (from bt in new BookTopic()
               where !bt.TopicId.Equals(1) && bt.Topic.Equals("abc")
               select bt).ToList().Count;

希望对您有所帮助.

I hope this helps you well.

u可以在LINQ中使用条件计数
看到此链接
http://msdn.microsoft.com/en-us/vcsharp/aa336747#countConditional [ ^ ]

u can use conditional count in LINQ
see this link
http://msdn.microsoft.com/en-us/vcsharp/aa336747#countConditional[^]

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