Using ODBC SQL Gateway programmatically

Long time ago I did some connections to external databases (MySql and PostGres).
The essential parts such a connection are:

1) First, you have to create in your OS the corresponding ODBC Data Source entries
   (System-DSN) after installing the required DB-Driver

2) The connection

    set gtwConn=##class(%SQLGatewayConnection).%New(), gtwHandle=0
    
    if gtwConn.Connect(OdbcName, OdbcUser, OdbcPass) {
        if gtwConn.AllocateStatement(.gtwHandle) {
            // check gtwConn.GatewayStatus
            // etc.
        } else { write "Can't Allocate: "_OdbcName }
    } else { write "Can't connect to "_OdbcName }

3) SQL-Commands

    do gtwConn.CloseCursor(gtwHandle)
    if gtwConn.PrepareW(gtwHandle, sqlStatement) {
        if gtwConn.Execute(gtwHandle) {
           ...
           ...
        } else { /* check gtwConn.GatewayStatus */ }
    } else { /* check.gtwConn.GatewayStatus */ }

   
4) Finish

    if gtwConn {
        do gtwConn.DropStatement(gtwHandle), gtwConn.Disconnect()
        set gtwConn="", gtwHandle=""
    }