CODEWITHSUNDEEP
vb.netms-accesstransactions
John
John

Reputation:

How to implement transaction way in vb.net?

I develop one application using VB.net (200%) that connects to MS-Access Database, I use TableAdapter and Dataset for connection to the Access DB file.

I need to implement a simple transaction method (commit, rollback) in saving to the DB?

Is there a way to do that without the need to use inline SQL statement?

Thanks,

Upvotes: 1

Views: 24720

Answers (2)

artur02
artur02

Reputation: 4479

As I read Microsoft Jet (Access DB Engine) supports transactions. So you can create a transaction like this (example from CodeProject):

      SqlConnection db = new SqlConnection("connstringhere");
      SqlTransaction transaction;

      db.Open();
      transaction = db.BeginTransaction();
      try 
      {
         new SqlCommand("INSERT INTO TransactionDemo " +
            "(Text) VALUES ('Row1');", db, transaction)
            .ExecuteNonQuery();
         new SqlCommand("INSERT INTO TransactionDemo " +
            "(Text) VALUES ('Row2');", db, transaction)
            .ExecuteNonQuery();
         new SqlCommand("INSERT INTO CrashMeNow VALUES " +
            "('Die', 'Die', 'Die');", db, transaction)
            .ExecuteNonQuery();
         transaction.Commit();
      } 
      catch (SqlException sqlError) 
      {
         transaction.Rollback();
      }
      db.Close();

An easier way is (example from 15 Seconds):

bool IsConsistent = false;

using (System.Transactions.TransactionScope ts = new System.Transactions.TransactionScope())

{

      SqlConnection cn = newSqlConnection(CONNECTION_STRING );

      string sql = "DELETE Categories";

      SqlCommand cmd = newSqlCommand(sql, cn);

      cn.Open();

      cmd.ExecuteNonQuery();

      cn.Close();

      //Based on this property the transaction will commit if

      //successful.  If it fails however, this property will

      //not be set and the transaction will not commit.

      ts.Consistent = IsConsistent;

}

You will need MSDTC running on your machine if you are using TransactionScope.

Unfortunately TableAdapter does not expose a connection property, so you need a workaround. So you need some workaround:

1) Reflection (example form CodeProject)

conn = new SqlConnection(Properties.Settings.Default.NorthwindConnectionString);
conn.Open();
trans = conn.BeginTransaction();
1. 
public SqlDataAdapter GetAdapter(object tableAdapter)
{
    Type tableAdapterType = tableAdapter.GetType();
    SqlDataAdapter adapter = (SqlDataAdapter)tableAdapterType.GetProperty("Adapter", BindingFlags.Instance | BindingFlags.NonPublic).GetValue(tableAdapter, null);
        return adapter;
}
2.
adapter.InsertCommand.Connection = trans.Connection;
adapter.UpdateCommand.Connection = trans.Connection;
adapter.DeleteCommand.Connection = trans.Connection;

3.
adapter.InsertCommand.Transaction = trans;
adapter.UpdateCommand.Transaction = trans;
adapter.DeleteCommand.Transaction = trans;

4. 
-

5. 
trans.commit();

Reflection can be very slow!

2) TransactionScope (example form DevX.com)

    CustomersDataSet.CustomersDataTable customers = new CustomersDataSet.CustomersDataTable();
   CustomersDataSetTableAdapters.CustomersTableAdapter tblAdap = new 
      CustomersDataSetTableAdapters.CustomersTableAdapter();
   using (TransactionScope txScope = new TransactionScope())
   {
       tblAdap.Fill(customers);
       customers.Rows[0]["ContactName"] = "Maria Velasquez";
       tblAdap.Update(customers);
       txScope.Complete();
   }

You will need MSDTC!

Upvotes: 11

user38123
user38123

Reputation: 669

You can find a bunch of data access tutorials at http://www.asp.net/learn/data-access/

Upvotes: -2

Related Questions