How do you change the SQL isolation level from Python using MySQLdb?

The documentation I've run across researching this indic开发者_开发问答ates that the way to do it for other databases is to use multiple statements in your query, a la:

>>> cursor = connection.cursor()
>>> cursor.execute("set session transaction isolation level read uncommitted; 
                    select stuff from table; 
                    set session transaction isolation level repeatable read;")

Unfortunately, doing that yields no results, as apparently the Python DB API (or maybe just this implementation of it?) doesn't support multiple recordsets within a single query.

Has anyone else had success with this in the past?

I don't think this works for the MySQLdb driver; you'll have to issue separate queries:

cur = conn.cursor()
cur.execute("SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED")
cur.execute("SELECT @@session.tx_isolation")
print cur.fetchall()[0]
cur.execute("SELECT * FROM bar")
print cur.fetchall()
cur.execute("SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ")
cur.execute("SELECT @@session.tx_isolation")
print cur.fetchall()[0]

# output
('READ-UNCOMMITTED',)
(('foo',), ('bar',))
('REPEATABLE-READ',)

The MySQLdb cursor's execute() method only sees the first query up to the semicolon:

cur.execute("SELECT * FROM bar WHERE thing = 'bar'; SELECT * FROM bar")
print cur.fetchall()

# output
(('bar',),)

cur.executemany("SELECT * FROM bar WHERE thing = 'bar'; SELECT * FROM bar")
print cur.fetchall()

use cur.executemany to run multiple sql statements with ; separated.