Column does not belong to table

[majidkorai]

Hey

Guyz I am having problem when i read the data from a datareader into a data table.

The whole scenario is this that I want to read data from two diffrent databases, the table strcutre is same. You can say that other one is the copy of 1st one. I want to read out the data from one table in one database and merge the results with the one read form the other database.

What i am doing is reading data from two databases into data readers. now i just have to merge them. what i did took one datatable and want to merge the data in two datareader object into that data table. frst one went ok. but when i was inserting the rows from the 2nd one it gave this error.
see the code bellow and suggest plz:

public static DataTable PopupateDataTableFromDataReader(DataTable dt, clsDataReader dr)
		{
			
			DataTable dtSchema = dr.dr.GetSchemaTable();
			
			// You can also use an ArrayList instead of List<>
			ArrayList listCols = new ArrayList();
           
			if (dtSchema != null)
			{
				foreach (DataRow drow in dtSchema.Rows)
				{
					string columnName = System.Convert.ToString(drow["ColumnName"]);
					DataColumn column = new DataColumn(columnName, (Type)(drow["DataType"]));
					column.Unique = (bool)drow["IsUnique"];
					column.AllowDBNull = (bool)drow["AllowDBNull"];
					column.AutoIncrement = (bool)drow["IsAutoIncrement"];
					listCols.Add(column);
					if(dt.Columns.IndexOf(column.ColumnName) == -1)
					{
						dt.Columns.Add(column);
					}
				}
			}
 
			// Read rows from DataReader and populate the DataTable
			while (dr.dr.Read())
			{
				DataRow dataRow = dt.NewRow();
				for (int i = 0; i < listCols.Count; i++)
				{
					dataRow[((DataColumn)listCols[i])] = dr.dr[i];
				}
				dt.Rows.Add(dataRow);
			}
			return dt;
		}	

		public static clsDataReader  executeReturn2(string sqlCommand)
		{
			try
			{

				SqlConnection   co =initConnection(2);
				clsDataReader dataReader=new clsDataReader();
				SqlCommand   myCommand = new SqlCommand(sqlCommand, co);
				SqlDataReader dr= myCommand.ExecuteReader();
				dataReader.co =co ;
				dataReader.dr =dr;
			
				return dataReader;
			}
			catch(Exception e)
			{
				throw new Exception("An error occured while trying to run the following: " + sqlCommand,e); 
			}
		}

[PRR]

If you wish to merge two similar tables then DataSet.Merge() is far easier to use. You have to make sure that the primary key column exists though.

Merging Datasets

To give a brief idea consider a table Emp1: with columns empid, empname and second table Emp2: with columns empid, empjoindate.
You could have data of Emp1 in dataset1 and Emp2 in dataset2.

select empid,empname from Emp1;
select empid,empjiondate from Emp2;

You could easily merge the dataset by calling

dataset1.Merge(dataset2.Tables[0]);