Shawn Wildermuth's Rants and Raves

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DataSet Updater Helper Method
DataSet Updater Helper Method
January 19, 2005

For some time now I’ve been pushing the idea of doing DataSet updates using DataAdapters that use a 1-to-1 relationship between DataAdapter and logical data elements (e.g. Tables or Stored Procedures usually).  This is especially true when you are dealing with related tables in DataSets (the sweet spot for DataSets IMHO).  I’ve continually forgotten to post this code that I use to do these updates.  The idea of this code is for the user to provide arrays of Tables and DataAdapters that imply the order of the updates.  For example

// Array of DataTables from a Typed
 DataSetDataTable[] updateTables = new DataTable[] 
// Array of DataAdapters
DataAdapter[] updateAdapters = 
  new DataAdapter[] 
// Call the Update Method
UpdateDataSet(updateTables, updateAdapters);

This implies the order so that the helper function can do the right thing which is to delete bottom up, and insert/update top down:

// Enforces that updates will be written in the right order.
internal static void UpdateDataSet(DataTable[] tables, SqlDataAdapter[] adapters)
  // Validate the input  
  if (tables.Length == 0 || adapters.Length == 0)
    throw new ArgumentException("You must send at least one table and adapter");  
  if (tables.Length != adapters.Length)  
    throw new ArgumentException("The number of tables and adapters must be identical");  
  // Disable Constraints until end of process  tables[0].DataSet.EnforceConstraints = false;
  using (SqlConnection conn = DataFactory.GetConnection() as SqlConnection)  {    SqlTransaction tx = null;
    // Try and update the datasets with a transaction    try    {      // Open the connection      conn.Open();
      // Start a transaction      tx = conn.BeginTransaction();
      // Set the Upper and Lower Bounds      int min = tables.GetLowerBound(0);      int max = tables.GetUpperBound(0);
      // Go through all the tables, and delete the deleted items (in reverse order)      for (int x = max; x >= min; --x)      {        DataRow[] updatingRows = tables[x].Select("", "", DataViewRowState.Deleted);        if (updatingRows != null && updatingRows.Length > 0)         {          adapters[x].DeleteCommand.Connection = conn;          adapters[x].DeleteCommand.Transaction = tx;          adapters[x].Update(updatingRows);        }      }
      // Go through all tables and update/insert the items (in forward order)      for (int x = min; x <= max; ++x)      {        DataRow[] updatingRows = tables[x].Select("", "", DataViewRowState.Added | DataViewRowState.ModifiedCurrent);        if (updatingRows != null && updatingRows.Length > 0)         {          adapters[x].InsertCommand.Connection = conn;          adapters[x].InsertCommand.Transaction = tx;          adapters[x].UpdateCommand.Connection = conn;          adapters[x].UpdateCommand.Transaction = tx;          adapters[x].Update(updatingRows);                }      }
      // Commit the transaction      tx.Commit();
      // Mark all the items as accepted      for (int x = min; x <= max; ++x)      {        tables[x].AcceptChanges();      }
    }    catch (Exception ex)    {      if (tx != null) tx.Rollback();      throw new ApplicationException("Failed to Update the database", ex);    }    finally    {      if (conn.State == ConnectionState.Open) conn.Close();
      if (tx != null) tx.Dispose();
      // Enable Constraints until end of process      tables[0].DataSet.EnforceConstraints = true;
    }  }}

This will eventually make it into the PowerToys project, but I haven’t had time to refactor it yet. HTH