How can I implement String.Concat(object, object) to L2E framework?

Question

I have two long type columns that I want to concat during sql query. Using Linq to Entities making it impossible, because it only supports String.Concat(string, string).

I'd like to know how can I implement this function myself and add it to the L2E framework.

score 1 · Accepted Answer · answered Jun 03 '10 at 12:40

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What's the point in doing the concat in SQL ? You can do it in a projection when you receive the data :

var query = from foo in db.Foo
            select new { foo.X, foo.Y };

var result = from foo in query.AsEnumerable()
             select foo.X.ToString() + foo.Y.ToString();

I'd like to know how can I implement this function myself and add it to the L2E framework.

I don't think that's possible, unless you want to implement your own EF provider...

answered Jun 03 '10 at 12:40

Thomas Levesque

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I was thinking about extending it. – Eran Betzalel Jun 03 '10 at 15:09
I doubt that is possible... If you want to know more about how the provider is implemented, have a look at it using Reflector. I suggest you buy a stock of aspirin beforehand ;) – Thomas Levesque Jun 03 '10 at 15:12

score 0 · Answer 2 · edited May 23 '17 at 11:55

0

~~Can't you convert them to strings first, by doing String.Concat(long1.ToString(), long2.ToString())? Or is this not understood by the framework either?~~

Take a look at this question, which talks about some workarounds for this problem. Maybe you can adapt something to work here as well?

edited May 23 '17 at 11:55

Community

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answered Jun 03 '10 at 08:59

lc.

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ToString() is not supported by L2E. Look here: http://msdn.microsoft.com/en-us/library/bb738681.aspx – Eran Betzalel Jun 03 '10 at 09:03
@Eran Betzalel I see. After a bit of digging, this looks like a common problem - there are a few related questions on SO. Not sure if it's helpful, but would be at least worth a look. – lc. Jun 03 '10 at 09:13
The solution on these questions is not for me (my current situation suggests that using ToList will simply get all the table's content). – Eran Betzalel Jun 03 '10 at 10:45

How can I implement String.Concat(object, object) to L2E framework?

2 Answers2