Transform a DataTable into Dictionary C#

Maximus Decimus picture Maximus Decimus · Oct 31, 2013 · Viewed 79.8k times · Source

I want to know how to transform a DataTable into a Dictionary. I did something like this.

using System.Linq;

internal Dictionary<string,object> GetDict(DataTable dt)
{
    return dt.AsEnumerable()
      .ToDictionary<string, object>(row => row.Field<string>(0),
                                row => row.Field<object>(1));
}

But I get:

System.Data.EnumerableRowCollection does not contains a definition for 'ToDictionary' and the best extension method overload 'System.Linq.Parallel.Enumerable.ToDictionary(System.Linq.ParallelQuery, System.Func, System.Collections.Generic.IEqualityComrparer)' has some invalid argumentsch

How can I resolve this?

Thanks

Answer

cadrell0 picture cadrell0 · Oct 31, 2013

The generic method ToDictionary has 3 parameters. You left one off, so it doesn't know what to do. If you want to specify all of the parameters, it would be <DataRow, string, object>.

internal Dictionary<string,object> GetDict(DataTable dt)
{
    return dt.AsEnumerable()
      .ToDictionary<DataRow, string, object>(row => row.Field<string>(0),
                                row => row.Field<object>(1));
}

Of course, if you leave them off, the compiler is able to infer the types, so you don't get the error.