Linq. Select

[shapper]

Hello,

I have the following LINQ:

List<Tagtags = (from t in
database.Tags
select t).ToList();

I need to restrict my results and for that I have two parameters:
StartWidth and N
I would like to change my Linq query to do as follows:

1. Select all tags which tag.Name starts with the value contained in
StartWidth parameter.
NOTE: Both tag.Name and StartWidth are strings.

AND

2. Get the first N tags from that list ordered alphabetically.
NOTE: If N = 0 then get all tags

How can I do this?

Thanks,
Miguel

[Jeroen Mostert]

shapper wrote:

I have the following LINQ:

List<Tagtags = (from t in
database.Tags
select t).ToList();

I need to restrict my results and for that I have two parameters:
StartWidth and N
I would like to change my Linq query to do as follows:

1. Select all tags which tag.Name starts with the value contained in
StartWidth parameter.

StartWidth or StartsWith? The latter would make more sense.

NOTE: Both tag.Name and StartWidth are strings.

AND

2. Get the first N tags from that list ordered alphabetically.

Alphabetically by what? I assume "Name".

NOTE: If N = 0 then get all tags

How can I do this?

Well, just write it down in steps. This is all tags:

from t in database.Tags
select t

Now we want all tags where tag.name starts with "StartsWith " (I assume). So:

from tag in database.Tags
where tag.Name.Starts With(StartsWith )
select tag

We want them ordered by Name:

from tag in database.Tags
where tag.Name.Starts With(StartsWith )
orderby tag.Name
select tag

This is the sequence we want. Now we want to limit the number of elements,
for which LINQ offers the extension method "Take":

var q =
from tag in database.Tags
where tag.Name.Starts With(StartsWith )
orderby tag.Name
select tag;

List<Tagtags = (N 0 ? q.Take(N) : q).ToList();

And that's all there is to it. See also
http://msdn.microsoft.com/vcsharp/aa336746 for examples of LINQ in action.

--
J.

[shapper]

On Jul 11, 6:11*pm, Jeroen Mostert <jmost...@xs4al l.nlwrote:

shapper wrote:

I have the following LINQ:

* * * List<Tagtags = (from t in
database.Tags
* * * * * * * * * * * * * * * * *select t).ToList();

I need to restrict my results and for that I have two parameters:
StartWidth and N
I would like to change my Linq query to do as follows:

1. Select all tags which tag.Name starts with the value contained in
StartWidth parameter.

StartWidth or StartsWith? The latter would make more sense.

* * NOTE: Both tag.Name and StartWidth are strings.

AND

2. Get the first N tags from that list ordered alphabetically.

Alphabetically by what? I assume "Name".

* * NOTE: If N = 0 then get all tags

How can I do this?

Well, just write it down in steps. This is all tags:

* *from t in database.Tags
* *select t

Now we want all tags where tag.name starts with "StartsWith " (I assume). So:

* *from tag in database.Tags
* *where tag.Name.Starts With(StartsWith )
* *select tag

We want them ordered by Name:

* *from tag in database.Tags
* *where tag.Name.Starts With(StartsWith )
* *orderby tag.Name
* *select tag

This is the sequence we want. Now we want to limit the number of elements,
for which LINQ offers the extension method "Take":

* *var q =
* * *from tag in database.Tags
* * *where tag.Name.Starts With(StartsWith )
* * *orderby tag.Name
* * *select tag;

* *List<Tagtags = (N 0 ? q.Take(N) : q).ToList();

And that's all there is to it. See alsohttp://msdn.microsoft. com/vcsharp/aa336746for examples of LINQ in action.

--
J.

Thank You!

Nice tip that web site ... I am just checking the examples.

Cheers,
Miguel