I'm porting a Java application to .NET. And it seems that ADO.NET is
not as good as JDBC in some ways.
In Java/JDBC you can have several open ResultSets with the same
connection. In ADO.NET you have to close an open DataReader before you
can open the next DataReader with the same connection.
What I want to do:
- I want to read objects with an 1:m relation (I call them "1-objects"
and "m-objects").
- I want to read the 1-objects one by one and read for every
1-objects the associated m-objects.
- I don't want to read *all* 1-objects first before I
start to read associated "m-objects".
- I want to read all objects (1 and m) in the same transaction.
Here's the C# pseudo code what I want to do:
,----
| IDbConnection connection;
| IDbComman command;
| IDataReader reader, reader2;
|
| // open a connection
| connection = new MySqlConnection();
| connection.Open();
|
| // start reading "1-objects"
| command = connection.CreateCommand();
| command.CommandText = "SELECT ...";
| reader = command.ExecuteReader();
|
| while (reader.Read())
| {
| // read "m-objects"
|
| // Open a second IDataReader before closing the first:
| // ok in Java, not ok in .NET!!!
|
| command = connection.CreateCommand();
| command.CommandText = "SELECT ...";
| reader2 = command.ExecuteReader();
| while (reader2.Read()) { ... }
|
| reader2.Close();
| }
|
| reader.Close();
`----
I could use a second connection for reading m-objects but then I'm not
in the same transaction as with the first connection.
How can I do in ADO.NET what I can do with JDBC? Any solution to
circumvent this limitation in ADO.NET?
Thanks,
Burkhard
