How to get the particular rows from the IList

MuraliAluri · **Joined:** Mon Apr 03, 2006 2:04 am **Posts:** 4

Hi,

i hava a list of values in my IList.
i want to show only particular rows in my grid from that list.
how to get only selected rows from the list.
please help me regarding this.

Thanks,
Murali

merge_s.rottem · **Joined:** Tue Aug 23, 2005 5:52 am **Posts:** 335

Hi MuraliAluri,

From the NHibernate documentation:

Quote:

9.3.3. Filtering collections

A collection filter is a special type of query that may be applied to a persistent collection or array. The query string may refer to this, meaning the current collection element.

Code:

ICollection blackKittens = session.Filter(
    pk.Kittens, "where this.Color = ?", Color.Black, NHibernateUtil.Enum(typeof(Color))
);

The returned collection is considered a bag.

Does that help?

Cheers,

Symon.

adelaid · **Joined:** Tue Mar 21, 2006 4:18 pm **Posts:** 11

This is not exact answer. Filter method search in collection, which is binded to some class. But what about situation, when IList is result of some Criteria query, it means without "master" object. Could you still use Filter method? In my opinion not.

merge_s.rottem · **Joined:** Tue Aug 23, 2005 5:52 am **Posts:** 335

I see your point. The answer is...not that I'm aware of. If you want a specific subset of data that's not from a persistent collection then you'd probably need to query for it explicitly (which is in effect what the .Filter method does internally - it's creating a new SQL query and adding the additional criteria specified to the normal criteria used to get the collection); eg. perform another Criteria query that includes the additional criteria you need to get the specific subet of data you need.

Symon.

devonl · **Posted:** Tue May 16, 2006 11:11 am

agree with merge. only other option would be to use a foreach loop in your code to check for the particular condition (row) you are looking for:

Code:

ArrayList matchedObjects = new ArrayList();

foreach (Object obj in myListOfQueriedObjects) {
    if (obj.Property == someCondition) {
        matchedObjects.Add(obj);
    }
}

DataGrid myDG;
myDG.DataSource = matchedObjects;
myDG.DataBind();

however, this really isn't good OO design. business logic now sits in the presentation layer...

-devon

adelaid · **Joined:** Tue Mar 21, 2006 4:18 pm **Posts:** 11

devonl wrote:

only other option would be to use a foreach loop in your code to check for the particulkar condition (row) you are looking for:

Yes, i have discovered it also. The goal was filter existing data without asking database again and again.

[/quote]
however, this really isn't good OO design. business logic now sits in the presentation layer...
-devon[/quote]

You are still able to put this code to some class in your business layer, like other app logic which have nothing to do with database.
Bye.

gert · **Joined:** Thu Jan 19, 2006 4:29 pm **Posts:** 348

devonl wrote:

however, this really isn't good OO design. business logic now sits in the presentation layer...

Without knowing the problem at hand You can't be sure. It might be purely presentation logic.

Gert

Patrik.H · **Posted:** Tue May 16, 2006 3:27 pm

Hi

Maybe npath can help you.. You can download a small demo from this url, http://blogs.wdevs.com/phirephly/archiv ... 12096.aspx