JPA and MySQL transaction isolation level

Question

I have a native query that does a batch insert into a MySQL database:

    String sql = \"insert into t1 (a, b) select x, y from t2 where x = \'foo\'\";
    E         


        

Answer 1

In JPA you don't. JDO is the only standard that supports setting txn isolation. Obviously going for particular implementations methods can allow it, but then you become non-portable

Answer 2

Since you are using BMT, you can do the following using a datasource to get the connection. and set the iso. level.

DataSource source = (javax.sql.DataSource) jndiCntxt.lookup("java:comp/env/jdbc/myds");
Connection con = source.getConnection( );
con.setTransactionIsolation(Connection.TRANSACTION_READ_UNCOMMITTED);

Answer 3

You need to set it at the connection level, get the session from the entitymanager and do this:

org.hibernate.Session session = (Session)entityManager.getDelegate();
Connection connection = session.connection();
connection.setTransactionIsolation(Connection.READ_UNCOMMITTED);