How to put a db selection result into an array? RSS

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  claudia888

  Member

  193 Points

  481 Posts

  How to put a db selection result into an array?

  Apr 28, 2012 09:41 PM|LINK

  HI,

  I'm building a MVC3 app. Can I use "ToArray()" to make a db selection result into an array? Here is an example:

  for (int i = 0; i < 5; i++)
              {
                  var rows = from c in db.Table1
                                   where ...
                                   select c.ColumnValue;
  
                  string[] newArray = new string[4];

  
                  newArray = rows.ToArray();   

  }

  Question: Is this correct? If not, how do I acheive what I want? I want to put the values in rows into an array.

  Or, Option2:

                  int i = 0;
                  foreach (var item in XYZ)
                  {
                      newArray[i] = item;
                      i++;
                  }

  Is this correct?

  Note: for both implementations above, I can compile the app, but when I run it, I get this error:

  The LINQ expression node type 'ArrayIndex' is not supported in LINQ to Entities.

  Thanks!!

  Claudia

  • Edited by claudia888 on Apr 28, 2012 09:47 PM
  • Edited by claudia888 on Apr 28, 2012 09:50 PM
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  IgorKitsula

  Member

  144 Points

  33 Posts

  Re: How to put a db selection result into an array?

  Apr 28, 2012 09:52 PM|LINK

  First, you don't need loop.

  Second - I would suggest to use List (List<string> in your case).

   var rows = from c in db.Table1
                                   where ...
                                   select c.ColumnValue;

  List<string> result = rows.ToList();

  or

  var = rows.ToList();

  or return list to the view:

  return View(rows.ToList())

  Please "Mark as answer", if my post helps you...
  - Igor
  Weblog: http://kitsula.com
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  Dan Bracuk

  Contributor

  3970 Points

  1096 Posts

  Re: How to put a db selection result into an array?

  Apr 28, 2012 10:15 PM|LINK

  Why do you need an array in the first place?  What do you want to do that you can't do with a datatable?

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  claudia888

  Member

  193 Points

  481 Posts

  Re: How to put a db selection result into an array?

  Apr 29, 2012 12:02 AM|LINK

  Hi IgorKitsula,

  Thanks for the input. I tried your suggestion "List<string> result = rows.ToList();" and "var = rows.ToList()", but got the same result as I had.

  When I run the app (F5), this line gave the same error message:

  The LINQ expression node type 'ArrayIndex' is not supported in LINQ to Entities.

  A question: in rows (after a db selection like this) - how is the information stored? in what format?

  Thanks,

  Claudia

  • Edited by claudia888 on Apr 29, 2012 12:03 AM
  • Edited by claudia888 on Apr 29, 2012 12:03 AM
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  IgorKitsula

  Member

  144 Points

  33 Posts

  Re: How to put a db selection result into an array?

  Apr 29, 2012 01:32 AM|LINK

  Can you provide complete code of your controller and view?

  Please "Mark as answer", if my post helps you...
  - Igor
  Weblog: http://kitsula.com