DevExpress formats columns differently if they're all numbers
Force the GridView column format from the code behind:

using DevExpress.Utils;
// ...
GridColumn myCol = new GridColumn() { Caption = "TheColumn", Visible = true, FieldName = "ColumnName" };
colPayment.DisplayFormat.FormatType = FormatType.String; //Char, Varchar, or whatever option DE gives you to format the display
gridView1.Columns.Add(myCol)


If you're gonna add it from the code behind, if not access the Column and set the format. 

gridView1.Columns["TheColumn"].DisplayFormat.FormatType = DevExpress.Utils.FormatType.String;


It is not an SQL issue, the data is stored in the format that is supposed to be stored, the frontend is the one supposed to handle the display format in this case. If you create a view the same deal will happen because the grid will still try to guess the column type. Talk to the dev.