Question

I need to insert JSON data from tornado to postgres, so here’s test like this:

from psycopg2 import connect

conn = connect("user='pguser' host='localhost' dbname='pgdb' password='pgpass'")
cursor = conn.cursor()

data = '[{"id":"sdf","name":"wqe","author":"vb"}]'

for row in eval(data):
  print row
  cursor.execute("""INSERT INTO books(id,name,author) VALUES('%s','%s','%s')""" % \
        (row['id'], row['name'], row['author'])
  )

>>> cursor.execute("SELECT * FROM books")
>>> cursor.fetchall()
[('sdf', 'wqe', 'vb')]
>>> 
$> psql -d pgdb -U pguser -W
Password for user pguser: 
psql (9.1.6)
Type "help" for help.

pgdb=> select * from books;
 id | name | author 
----+------+--------
(0 rows)

As you can see after doing select in python shell, there’s some data, but in psql there’s
0 rows! What may I be doing wrong?

Python 2.7.2+

Answer 1

You didn’t commit the transaction.

Psycopg2 opens a transaction automatically, and you must tell it to commit in order to make the data visible to other sessions.

See the psycopg2 FAQ and the connection.commit() method.