Passing Linq query results to a different function

Swiftain

Hi, I have the following linq code within my app var results = (from t in query where t.ProjectID == new Guid(this.Session["ProjectID"].ToString()) orderby t.Number ascending select new { ID = t.ID, Tag = t.Number, Description = t.Description, SubSystems = GeneralHelper.TagSubSystems(t), Module = t.Area.Module.Name, Discipline = t.Discipline.Name, ITRs = GeneralHelper.TagITRsHTML(t) }); I want to pass the query result to another function to handle my paging. I currently have another function defined like this public void BindGridData(IQueryable result) { gridView.DataSource = result; gridView.DataBind(); } It works like this, but the problem is I cannot do "take" or "skip" on "result" because it's declared as IQueryable. Is there a work around to handle this? Thanks

brunoseixas

convert the linq result to list

var results = (from t in query
where t.ProjectID == new Guid(this.Session["ProjectID"].ToString())
orderby t.Number ascending
select new
{
ID = t.ID,
Tag = t.Number,
Description = t.Description,
SubSystems = GeneralHelper.TagSubSystems(t),
Module = t.Area.Module.Name,
Discipline = t.Discipline.Name,
ITRs = GeneralHelper.TagITRsHTML(t)
}).ToList();

Swiftain

If I convert it to list, then how do I define the function that takes the query result?

Not Active

public void BindGridData(IEnumerable result)
{
gridView.DataSource = result;
gridView.DataBind();
}

Also note the use of the pre tags to properly format the code snippet

I know the language. I've read a book. - _Madmatt

Swiftain

IEnumerable requires an argument, IEnumerable result any idea what argument would work?

Ian Shlasko

Create a structure to represent your query results, instead of using anonymous types. Then you know what kind of IEnumerable it is. Alternatively, make your Bind function generic, like so:

public void BindGridData<T>(IEnumerable<T> result)
{
gridView.DataSource = result;
gridView.DataBind();
}

Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels)

Swiftain

That worked! Thanks.

Not Active

IEnumerable<T> requires a type but IEnumerable does not.

I know the language. I've read a book. - _Madmatt

modified on Tuesday, August 31, 2010 12:12 PM

Not Active

Although I agree a concrete type is better for readability and good design it isn't necessary in order to pass the query to a method.

I know the language. I've read a book. - _Madmatt

Swiftain

the reason i didnt define a concrete type is because the function will be accepting queries from different classes

Swiftain · modified on Tuesday, August 31, 2010 12:12 PM

???

Not Active

Sorry, the brackets didn't render. Fix it

I know the language. I've read a book. - _Madmatt

Ian Shlasko

Ok, then the second solution is best :) Oh, and you don't need to do a ToList() if you're going that route. Linq results are all IEnumerable.

Proud to have finally moved to the A-Ark. Which one are you in?
Author of the Guardians Saga (Sci-Fi/Fantasy novels)

Not Active

Using generics, as Ian has suggested, doesn't preclude you from doing that. You would just need to create the class/struct for each query, which from a architectural perspective isn't a bad idea. However, if you have many different queries that are possible then perhaps you need to improve your design, one size fits all implementation are very difficult to maintain.

I know the language. I've read a book. - _Madmatt

Swiftain

One more thing, lets say I store "result" in session variable like this public void BindGridData(IEnumerable result) { Session["result"] = result; gridView.DataSource = result; gridView.DataBind(); } and then I want to call this function within another event, how do I call it? how do I cast Session["result"]? Thanks

Not Active

First of all don't store it in session state. Remember this is the result of your query, not the query itself, and could be very large. It's also quite clear how to cast it. It is being passed into your method as an IEnumerable, guess what it should be cast as?

I know the language. I've read a book. - _Madmatt