Join Two Data Tables

public static DataTable JoinTable(DataTable firstTable, DataTable secondTable, string firstTableKey, string secondTableKey)

{

DataTable dtResults = secondTable.Clone();

foreach (DataColumn dataColumn in firstTable.Columns)

{

if (!dtResults.Columns.Contains(dataColumn.ColumnName))

dtResults.Columns.Add(dataColumn.ColumnName, typeof(string));

}

foreach (DataRow dataRow in firstTable.Rows)

{

DataRow dtRow = dtResults.NewRow();

foreach (DataColumn dataColumn in firstTable.Columns)

{

dtRow[dataColumn.ColumnName] = dataRow[dataColumn.ColumnName].ToString();

}

foreach (DataRow finalRow in secondTable.Select("[" + secondTableKey + "] = '" + dataRow[firstTableKey].ToString() + "'"))

{

foreach (DataColumn dataColumn in secondTable.Columns)

{

dtRow[dataColumn.ColumnName] = finalRow[dataColumn.ColumnName].ToString();

}

break;

}

dtResults.Rows.Add(dtRow);

}

return dtResults;

}