# Connection.startTransaction

Start a database transaction on this connection.

### For an overview see page Python Connection Class

### Prototype

        Connection.startTransaction(type, priority)

### Arguments

type | The Transaction Type; one of the following values:
        MCO_READ_ONLY = 0
        MCO_UPDATE = 1
        MCO_READ_WRITE = 2
        MCO_EXCLUSIVE = 3
priority | The Transaction Priority; one of the following values:
        MCO_TRANS_IDLE       = -2
        MCO_TRANS_BACKGROUND = -1
        MCO_TRANS_FOREGROUND = 0
        MCO_TRANS_HIGH       = 1
        MCO_TRANS_ISR        = 2

### Description

This method starts a database transaction on this Connection. Note that nested transactions are not supported, so each connection can have only one opened transaction at a time.

### Returns

MCO_S_OK | Transaction started successfully
Exception | An exception is thrown with the appropriate error message

### Example

        conn = db.connect()
        print 'Database connected. Connection object is', conn
        #
        # Insert objects
        #
        i = 0
        while i < OBJECT_NUM:
            conn.startTransaction(exdb.Transaction.MCO_READ_WRITE) # start RW transaction
            rec = conn.new("Record") # create python object
            # fill data
            ...

            conn.commit() # commit changes
            i += 1

        print_database(conn, "Database content after insert :")