what are different transaction levels
Transaction levels are:
1) TRANSACTIONNONE: IF you dont set the transaction isolation or if you set it to TRANSACTIONNONE, the transaction executes according to the default isolation level of the underluing odbc driver.
2) TRANSACTIONREADUNCOMMITTED: A transaction reading the uncommitted data of a data source. A dirty read is possible, meaning that no shared locks are issued and no exclusive locks are honored.
3) TRANSACTIONREADCOMMITTED: A transaction reading the committed data of a data source. Shared locks are held while the data is being read to avoid dirty reads.
4) TRANSACTIONREPEATABLEREAD: Locks are placed on all data that is used in a query, preventing other users from updating the data.
5) TRANSACTION_SERIALIZABLE: A range lock is placed on the dataset Until the transaction is completed, preventing other users from updating or inserting rows into the dataset.