C# – Querying DataColumnCollection with LINQ

asqueryablecdatacolumncollectiondatatablelinq

I'm trying to perform a simple LINQ query on the Columns property of a DataTable:

from c in myDataTable.Columns.AsQueryable()
    select c.ColumnName

However, what I get is this:

Could not find an implementation of the query pattern for source type 'System.Linq.IQueryable'. 'Select' not found. Consider explicitly specifying the type of the range variable 'c'.

How can I get the DataColumnCollection to play nice with LINQ?

Best Answer

How about:

var x = from c in dt.Columns.Cast<DataColumn>()
        select c.ColumnName;

Related Solutions

C# – LINQ query on a DataTable

You can't query against the DataTable's Rows collection, since DataRowCollection doesn't implement IEnumerable<T>. You need to use the AsEnumerable() extension for DataTable. Like so:

var results = from myRow in myDataTable.AsEnumerable()
where myRow.Field<int>("RowNo") == 1
select myRow;

And as @Keith says, you'll need to add a reference to System.Data.DataSetExtensions

AsEnumerable() returns IEnumerable<DataRow>. If you need to convert IEnumerable<DataRow> to a DataTable, use the CopyToDataTable() extension.

Below is query with Lambda Expression,

var result = myDataTable
    .AsEnumerable()
    .Where(myRow => myRow.Field<int>("RowNo") == 1);

Linq – Multiple “order by” in LINQ

This should work for you:

var movies = _db.Movies.OrderBy(c => c.Category).ThenBy(n => n.Name)

Best Answer

Related Solutions

C# – LINQ query on a DataTable

Linq – Multiple “order by” in LINQ

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