https://community.blueprism.com/t5/Product-Forum/Append-Collection-Field-Type-to-an-existing-collection/m-p/85438#M36431 Hi All, I am trying to build a code stage to add a field type of "Collection" to an existing collection... but I can't find the relevant datatype to select. The below code is not being accepted by the BP Compiler:  If Not Collection.Columns.Contains(Column) Then  Collection.Columns.Add(Column, typeof(DataTable))  End If For Each dr As System.Data.DataRow In Collection.Rows  dr(Column) = Value Next New_Collection = Collection   Getting these error messages: Compiler error at line 3: 'Is' expected. Compiler error at line 3: 'DataTable' is a type and cannot be used as an expression.   Any ideas would be greatly appreciated.   Mon, 09 Jul 2018 21:55:00 GMT asilarow 2018-07-09T21:55:00Z https://community.blueprism.com/t5/Product-Forum/Append-Collection-Field-Type-to-an-existing-collection/m-p/85438#M36431 Hi All, I am trying to build a code stage to add a field type of "Collection" to an existing collection... but I can't find the relevant datatype to select. The below code is not being accepted by the BP Compiler:  If Not Collection.Columns.Contains(Column) Then  Collection.Columns.Add(Column, typeof(DataTable))  End If For Each dr As System.Data.DataRow In Collection.Rows  dr(Column) = Value Next New_Collection = Collection   Getting these error messages: Compiler error at line 3: 'Is' expected. Compiler error at line 3: 'DataTable' is a type and cannot be used as an expression.   Any ideas would be greatly appreciated.   Mon, 09 Jul 2018 21:55:00 GMT https://community.blueprism.com/t5/Product-Forum/Append-Collection-Field-Type-to-an-existing-collection/m-p/85438#M36431 asilarow 2018-07-09T21:55:00Z https://community.blueprism.com/t5/Product-Forum/Append-Collection-Field-Type-to-an-existing-collection/m-p/85439#M36432 Try System.Type.GetType(""System.Data.DataTable"") instead of typeof(DataTable) Tue, 10 Jul 2018 05:20:00 GMT https://community.blueprism.com/t5/Product-Forum/Append-Collection-Field-Type-to-an-existing-collection/m-p/85439#M36432 John__Carter 2018-07-10T05:20:00Z https://community.blueprism.com/t5/Product-Forum/Append-Collection-Field-Type-to-an-existing-collection/m-p/85440#M36433 Cheers John, That didn't work (it was returning a null value), but it gave me a lead on how to solve it:  Dim a As Type  Dim b As DataTable         b = New DataTable         a = b.GetType() If Not Collection.Columns.Contains(Column) Then  Collection.Columns.Add(Column, a) End If New_Collection = Collection   :-) Regards, Andrzej. Tue, 10 Jul 2018 23:34:00 GMT https://community.blueprism.com/t5/Product-Forum/Append-Collection-Field-Type-to-an-existing-collection/m-p/85440#M36433 asilarow 2018-07-10T23:34:00Z