I'm having trouble with MySQL or Python and can't seem to isolate the problem. INSERTs only seem to last the run of the script and are not stored in the database.

I have this script:

import MySQLdb
db = MySQLdb.connect(host="localhost", user="user", passwd="password", db="example")
dbcursor = db.cursor()

dbcursor.execute("select * from tablename")
temp = dbcursor.fetchall()
print 'before: '+str(temp)

dbcursor.execute('INSERT INTO tablename (data1, data2, data3) VALUES ("1", "a", "b")')

dbcursor.execute("select * from tablename")
temp = dbcursor.fetchall()
print 'after: '+str(temp)

The first time I run it I get the expected output:

>>> 
before: ()
after: ((1L, 'a', 'b'),)

The problem is that if I run it again, the before comes out empty when it should already have the entry in it and the after doesn't break (data 1 is primary key).

>>> 
before: ()
after: ((1L, 'a', 'b'),)
>>> 
before: ()
after: ((1L, 'a', 'b'),)
>>> 
before: ()
after: ((1L, 'a', 'b'),)

If I try running the insert command twice in the same script it will break ("Duplicate entry for PRIMARY KEY")

Any idea what might be happening here?