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LINQ - Select records

Hello,

I have 3 SQL tables:

[Tags] TagId, TagText
[Posts] PostId, TagId, ...
[Files] FileId, TagId, ...

I need to, using LINQ, select all records in Tags, including the
columns TagId and TagText, but adding a new column of type boolean
which is True if the tag is associated to a Post OR to a File, i.e.,
if the TagId exists in Posts or Files.

How can I do this?

Thanks,
Miguel

Nov 8 '07 #1
3 8134
Miguel,

Have you used the new O/RM tool within Visual Studio 2008 to create the db
context?

You should then be able to express:

var query = from t in db.Tags
select new
{
TagId = t.TagId,
TagText = t.TagText,
hasPosts = t.Posts 0,
hasFiles = t.Files 0
};

This is supposed to work because LINQ to SQL exposes the foreign key
relationship as a collection at the object level.

Please lest me/us know how it goes!

Best regards
-Ralf

http://www.24100.net
"shapper" <md*****@gmail.comwrote in message
news:11**********************@o3g2000hsb.googlegro ups.com...
Hello,

I have 3 SQL tables:

[Tags] TagId, TagText
[Posts] PostId, TagId, ...
[Files] FileId, TagId, ...

I need to, using LINQ, select all records in Tags, including the
columns TagId and TagText, but adding a new column of type boolean
which is True if the tag is associated to a Post OR to a File, i.e.,
if the TagId exists in Posts or Files.

How can I do this?

Thanks,
Miguel
Nov 8 '07 #2
Did it work? Any feedback?
"Ralf Rottmann" <Be*****@live.comwrote in message
news:BD**********************************@microsof t.com...
Miguel,

Have you used the new O/RM tool within Visual Studio 2008 to create the db
context?

You should then be able to express:

var query = from t in db.Tags
select new
{
TagId = t.TagId,
TagText = t.TagText,
hasPosts = t.Posts 0,
hasFiles = t.Files 0
};

This is supposed to work because LINQ to SQL exposes the foreign key
relationship as a collection at the object level.

Please lest me/us know how it goes!

Best regards
-Ralf

http://www.24100.net
"shapper" <md*****@gmail.comwrote in message
news:11**********************@o3g2000hsb.googlegro ups.com...
>Hello,

I have 3 SQL tables:

[Tags] TagId, TagText
[Posts] PostId, TagId, ...
[Files] FileId, TagId, ...

I need to, using LINQ, select all records in Tags, including the
columns TagId and TagText, but adding a new column of type boolean
which is True if the tag is associated to a Post OR to a File, i.e.,
if the TagId exists in Posts or Files.

How can I do this?

Thanks,
Miguel
Nov 9 '07 #3
On Nov 9, 2:50 pm, "Ralf Rottmann \(www.24100.net\)"
<BeSh...@live.comwrote:
Did it work? Any feedback?

"Ralf Rottmann" <BeSh...@live.comwrote in message

news:BD**********************************@microsof t.com...
Miguel,
Have you used the new O/RM tool within Visual Studio 2008 to create the db
context?
You should then be able to express:
var query = from t in db.Tags
select new
{
TagId = t.TagId,
TagText = t.TagText,
hasPosts = t.Posts 0,
hasFiles = t.Files 0
};
This is supposed to work because LINQ to SQL exposes the foreign key
relationship as a collection at the object level.
Please lest me/us know how it goes!
Best regards
-Ralf
http://www.24100.net
"shapper" <mdmo...@gmail.comwrote in message
news:11**********************@o3g2000hsb.googlegro ups.com...
Hello,
I have 3 SQL tables:
[Tags] TagId, TagText
[Posts] PostId, TagId, ...
[Files] FileId, TagId, ...
I need to, using LINQ, select all records in Tags, including the
columns TagId and TagText, but adding a new column of type boolean
which is True if the tag is associated to a Post OR to a File, i.e.,
if the TagId exists in Posts or Files.
How can I do this?
Thanks,
Miguel
Hello,

Sorry, I was out of work. I didn't try it yet.

I was trying to put this in a LINQ Data Source.

This is something I am not sure. Is it possible to use any LINQ query
in a LINQ Data Source?

Thanks,
Miguel

Nov 9 '07 #4

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