Problem with Linq To Sql - Entity Framework

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Hi, I have problem with Linq To Entity. I have 2 table called Member and Payment. I use Linq code to retrieve the data. Here's the code:

Array array = (from member in container.Member
		join payment in container.Payment
		on member.MemberCode equals payment.MemberCode
		select new { member.Name, member.Rank, payment.DatePaid, payment.Remarks }).ToArray();

My question is: how to get each element of this array? I want to add each element into ListView.
It's easy to set array as DataGridView data source by writing dataGridView.DataSource = list;
All I want here is to get each element of this array because I need to loop them and insert them into ListView.
I can't access it with this line because this array contains both Member and Payment.

C#

string nm = string.Empty;
string dp = string.Empty;
foreach(Member m in array)
{
    nm = m.Name; 
    dp = m.DatePaid //It can't
}

Posted 8-Aug-12 6:42am

derodevil

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Philip Stuyck · Accepted Answer · 2012-08-08T06:49:00

Solution 1

The reason you can't is because you are using an anonymous type.
Try this instead

C#

var array = (from member ...
foreach(var t in array){
}

Then using the debugger you can check what members t has. Probably name, rank and datepaid and remarks

Posted 8-Aug-12 6:49am

Philip Stuyck

Updated 8-Aug-12 7:59am

v2

Comments

derodevil 8-Aug-12 12:58pm

Yes, you're right. And how to get the values?
this code still generates errors
string nm = string.Empty;
string dp = string.Empty;
foreach(var t in array)
{
nm = t.Name;
dp = t.DatePaid;
}

Philip Stuyck 8-Aug-12 13:18pm

well, if DatePaid is a DateTime structure, then assigning it on a string won't work. either change dp to DateTime or use dp=t.DatePaid.toString().
Please mark this as a solution to give me credit for it.
If this is not the problem then tell me the compilaton error and the line where it complains about.

derodevil 8-Aug-12 13:22pm

I still can't access the property values. t.Name error, t has no property named Name and DatePaid.

Philip Stuyck 8-Aug-12 13:47pm

I told you to use a debugger to find out the proper names but if you do this :
select new {Name= member.Name,Rank= member.Rank,DatePaid= payment.DatePaid,...
then you are forcing the anonymous type members to have member names defined by yourself.

Philip Stuyck 8-Aug-12 14:15pm

Also take the PS of Zoltan into account. You don't need toArray(). It works perfectly well without it too.

derodevil 10-Aug-12 13:34pm

Ok, thank you philip for answering my question.

derodevil 10-Aug-12 13:34pm

Thank you philip for answering my question. Thanks a lot.

**Zoltán Zörgő** · Accepted Answer · 2012-08-08T08:01:00

1) You can not cast implicitly between well-known and anonymous classes.
2) The array you construct is not an array of Member
Here are your options:
Method 1)
Define a class that contains all four members you want to return as result, and select the result as enumeration of that class (...select new classname { Name=Memeber.name, .... and foreach(classname m in array)...)
Method 2)
You can use reflection to read the member values. This is an overhead, thus be careful.
Method 3)
Declare the array also as anonymous (var array=(from... and foreach(var m in array)...)
Method 4)
Use the new dynamic supertype (foreach(dynamic m in array)...)

I would rather use method 1.

PS: You should convert it to array only when really needed, since you miss the advantages of deferred execution.