Exporting an ADO.NET Connection to a Third-Party .NET Assembly
To export an ADO.NET connection from a PowerBuilder Classic
application, use the GetAdoConnection method:
1 |
oleobject GetAdoConnection() |
The method returns an instance of IAdoConnectionProxy.
The proxy’s ADO connection object is assigned to property IAdoConnectionProxy.Connection.
When a transaction starts, the proxy’s active Transaction
object is assigned to property IAdoConnectionProxy.Transaction,
and AutoCommit is false. When AutoCommit is
true, the exported IAdoConnectionProxy.Transaction is
null..
The method returns null if the connection fails, and false
if the operation fails.
To use the shared connection, your third-party assembly must
reference the exported connection proxy and manage the transaction.
To be notified when the active transaction is changed, you can subscribe
the IAdoConnection.TransactionChanged event .
Remember to close the connection.
Sample PowerScript Code
//Sample PowerScript code
SQLCA.DBMS = "ADO.NET"
SQLCA.AutoCommit = false
SQLCA.DBParm = "Namespace='System.Data.Odbc',
DataSource='SQL
Anywhere
11 Demo'"
Connect Using SQLCA;
emp.ConnectionProxy = SQLCA.GetAdoConnection()
// db
operations
disconnect using SQLCA;
Sample C# Code
Here is an example of C# code in the third-party
assembly:
// Manage the transaction
public
class Emp {
...
IAdoConnectionProxy
proxy;
IDbTransaction trans;
...
public
object ConnectionProxy {
get { return
proxy; }
set {
proxy = value
as IAdoConnectionProxy;
...
proxy.TransactionChanged += new
EventHandler(proxy_TransactionChanged);
}
}
void
proxy_TransactionChanged(object sender, EventArgs e) {
...
trans = sender
as IDbTransaction;
...
}
...
}