.NET: How to change the value in a DataTable - data-binding

Question

In ADO.NET i'm using GetSchemaTable to return the schema table for a results set.
DataTable schema = rdr.GetSchemaTable();
gridSchema.DataSource = schema;
gridSchema.DataBind();
Unfortunatly the "ProviderType" value is displaying as an integer, rather than the OleDbType enumeration value that it is:
ProviderType Desired Display Value
============ =====================
129 Char
3 Integer
129 Char
129 Char
3 Integer
3 Integer
129 Char
135 DBTimeStamp
129 Char
129 Char
...
All these integers are the the enumeration values for the OleDbType enumeration:
public enum OleDbType
{
Empty = 0,
SmallInt = 2,
Integer = 3,
Single = 4,
Double = 5,
Currency = 6,
Date = 7,
BSTR = 8,
IDispatch = 9,
Error = 10,
Boolean = 11,
Variant = 12,
IUnknown = 13,
Decimal = 14,
TinyInt = 16,
UnsignedTinyInt = 17,
UnsignedSmallInt = 18,
UnsignedInt = 19,
BigInt = 20,
UnsignedBigInt = 21,
Filetime = 64,
Guid = 72,
Binary = 128,
Char = 129,
WChar = 130,
Numeric = 131,
DBDate = 133,
DBTime = 134,
DBTimeStamp = 135,
PropVariant = 138,
VarNumeric = 139,
VarChar = 200,
LongVarChar = 201,
VarWChar = 202,
LongVarWChar = 203,
VarBinary = 204,
LongVarBinary = 205,
}
i want to display the data type as something human readable, rather than an integer.
i've tried looping through the schema DataTable and modify the values inside the DataTable:
DataTable schema = rdr.GetSchemaTable();
//Change providerType column to be readable
foreach (DataRow row in schema.Rows)
{
OleDbType t = (OleDbType)row["ProviderType"];
row["ProviderType"] = t.ToString();
}
gridSchema.DataSource = schema;
gridSchema.DataBind();
But that throws an exception:
Column 'ProviderType' is read only.
i even looked at the GridView's RowDataBound event, thinking i could change the value as it is rendered:
protected void gridSchema_RowDataBound(object sender, GridViewRowEventArgs e)
{
//todo: magic
//e.Row["ProviderType"]
}
But it doesn't look like you can play with rendered values.
Can anyone suggest a nice way to much with the value of the ProviderType column so that it is human readable when i display it to humans?
Update
The workaround i'm using right now is tack an extra column on the end:
DataTable schema = rdr.GetSchemaTable();
schema.Columns.Add("OleDbDataType", typeof(String));
schema.Columns.Add("CLRDataType", typeof(String));
foreach (DataRow row in schema.Rows)
{
//Show the actual provider type
OleDbType t = (OleDbType)row["ProviderType"];
row["OleDbDataType"] = t.ToString();
//Show the corresponding CLR type while we're doing a hack
row["CLRDataType"] = row["DataType"].ToString();
}
gridSchema.DataSource = schema;
gridSchema.DataBind();

Answer 1

I might be completely off here, but can't you just set the ReadOnly property of the column to false? Like:
schema.Columns["ProviderType"].ReadOnly = false;
Afterwards you might get a columntype problem as you're trying to put a string value into a integer column. But this should get you into the right direction.
edit:
Solving the columntype issue:
DataTable newTable = schema.Clone();
newTable.Columns["ProviderType"].DataType = typeof(string);
foreach (DataRow dr in schema.Rows)
{
DataRow newRow = newTable.NewRow();
// fill newRow with correct data and newly formatted providertype
newTable.Rows.Add(newRow);
}

Answer 2

Or you could create an object with all the fields from the datatable, pass all the data into your object and modify it or create a read only field that returns the string acording to the integer given.
GridView and other also accept object arrays as datasources so it is automatic.