mirror of
https://github.com/psycopg/psycopg2.git
synced 2024-11-10 19:16:34 +03:00
45 lines
1022 B
Python
45 lines
1022 B
Python
import psycopg2
|
|
import traceback
|
|
|
|
# Change the table here to something the user can create tables in ...
|
|
db = psycopg2.connect('dbname=test')
|
|
|
|
cursor = db.cursor()
|
|
|
|
print 'Creating tables and sample data'
|
|
|
|
cursor.execute('''
|
|
CREATE TEMPORARY TABLE foo (
|
|
id int PRIMARY KEY
|
|
)''')
|
|
cursor.execute('''
|
|
CREATE TEMPORARY TABLE bar (
|
|
id int PRIMARY KEY,
|
|
foo_id int,
|
|
CONSTRAINT bar_foo_fk FOREIGN KEY (foo_id) REFERENCES foo(id) DEFERRABLE
|
|
)''')
|
|
cursor.execute('INSERT INTO foo VALUES (1)')
|
|
cursor.execute('INSERT INTO bar VALUES (1, 1)')
|
|
|
|
db.commit()
|
|
|
|
print 'Deferring constraint and breaking referential integrity'
|
|
cursor.execute('SET CONSTRAINTS bar_foo_fk DEFERRED')
|
|
cursor.execute('UPDATE bar SET foo_id = 42 WHERE id = 1')
|
|
|
|
print 'Committing (this should fail)'
|
|
try:
|
|
db.commit()
|
|
except:
|
|
traceback.print_exc()
|
|
|
|
print 'Rolling back connection'
|
|
db.rollback()
|
|
|
|
print 'Running a trivial query'
|
|
try:
|
|
cursor.execute('SELECT TRUE')
|
|
except:
|
|
traceback.print_exc()
|
|
print 'db.closed:', db.closed
|