asked on

consuming the results of Linq query, convert to datatable

I have a LINQ query that selects records from the table.
1) I am wondering how can I convert this to datatable so I can bind this to a datagrid.
2) should I even be converting this to a datatable, is there a better way for working with the record set?
i am working in asp.net 4.0 application in vb.net
Any suggestions would be great. thanks

joriszwaenepoel

Do you mean the gridview control? The DataSource does not need to be a datatable. A List or other collection (LINQ query result) will work just as well for databinding.

myGridView.DataSource = from item in myList where ....

abhinayp86

Here is an example i use in my proj, for how to Linq-query a datatable n bind it to grdview(works for record set as well)

DataTable dtTemp = new DataTable();
        dtTemp = (DataTable)ViewState["table"];
        DataTable dtNewTable = new DataTable();
        dtNewTable = dtTemp.Copy();
        IEnumerable<DataRow> ienNewDataRow = default(IEnumerable<DataRow>);
ienNewDataRow = dtTemp.AsEnumerable()
                    .Where(t => t.Field<string>("CategoryNM") == ddlCategory.Text);
if (ienNewDataRow.Count() > 0)
                dtNewTable = ienNewDataRow.CopyToDataTable();
            else
                dtNewTable = dtTemp.Clone();
gvResults.DataSource = dtNewTable;
        gvResults.DataBind();

Open in new window

vivekpv10

for converting linq result into a datatable,use this function..
eg.
var drevlinq = from drelinq_obj in context.drev where userid == drelinq_obj.user_master.user_id select new { drelinq_obj.dreid };
DataTable devtab = LINQToDataTable(drevlinq);

public DataTable LINQToDataTable<T>(System.Collections.Generic.IEnumerable<T> varlist)
    {
        DataTable dtReturn = new DataTable();

        // column names 
        PropertyInfo[] oProps = null;

        if (varlist == null) return dtReturn;
    

        foreach (T rec in varlist)
        {
            // Use reflection to get property names, to create table, Only first time, others 
            //   will follow 
            if (oProps == null)
            {
                oProps = ((Type)rec.GetType()).GetProperties();
                foreach (PropertyInfo pi in oProps)
                {
                    Type colType = pi.PropertyType;

                    if ((colType.IsGenericType) && (colType.GetGenericTypeDefinition()
                    == typeof(Nullable<>)))
                    {
                        colType = colType.GetGenericArguments()[0];
                    }

                    dtReturn.Columns.Add(new DataColumn(pi.Name, colType));
                }
            }

            DataRow dr = dtReturn.NewRow();

            foreach (PropertyInfo pi in oProps)
            {
                dr[pi.Name] = pi.GetValue(rec, null) == null ? DBNull.Value : pi.GetValue
                (rec, null);
            }

            dtReturn.Rows.Add(dr);
        }
        return dtReturn;
    }

Open in new window

ASKER CERTIFIED SOLUTION

vivekpv10

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

TrialUser

ASKER

Vivek:

Ur code works great to convert to datatable. does what I wanted. Thanks a ton for posting the vb version.

But I was wondering if it is also possible to convert it to a typed dataset. I am opening that as a separate question tough.

If it is possible, please respond. Thanks a ton.