There is good example of an insert statement, explained step by step. If what you need to do is an update, just replace the sql command int the example, with the desired update statement.
-Importing the Namespaces
-create an OracleConnection object
Dim myOracleConnection As New OracleConnection( "User Id=store;Password=store;Data Source=ORCL")
-create an OracleTransaction object and start the transaction
Dim myOracleTransaction As OracleTransaction = myOracleConnection.BeginTransaction()
-create an OracleCommand object to store a SQL statement.
Dim myOracleCommand As OracleCommand = myOracleConnection.CreateCommand
-set the CommandText property of the OracleCommand object
myOracleCommand.CommandText = "INSERT INTO product_types (" & " product_type_id, name" & ") VALUES (" & " 3, 'Magazine'" & ")"
-run the sql statement
-commit the transaction in the database
-close the OracleConnection