psycopg2

问题 I have a table in my db called 'mytable'. I'd like to clear it so that I can continue to collect and analyze 'fresh data' from it. Something like conn = psycopg2.connect(database = mydb_name, host = mydb_server, user = mydb_uname, password = mydb_pwd) cur = conn.cursor() cur.execute("DROP TABLE mytable;") Isn't going to work for me, because as far as I understand it, this destroys the table. I don't want to destroy/re-create... Just to flush all data. How can I work this out? 回答1: Truncate

问题 I have several occasions where I want to collect data when in the field. This is in situations where I do not always have access to my postgres database. To keep things in sync, it would be excellent if I could use psycopg2 functions offline to generate queries that can be held back and once I am able to connect to the database; process everything that is held back. One thing I am currently struggling with is that the psycopg2 cursor requires a connection to be constructed. My question is: Is

问题 It's my first time using PostgreSQL 8.4.2 with Django(I have always used MySQL or sqlite3 in the past). Which value should I use for DATABASE_ENGINE in settings.py , postgresql_psycopg2 or postgresql ? How do they differ from each other? 回答1: Update for Django 1.9 The django.db.backends.postgresql_psycopg2 backend has been renamed to django.db.backends.postgresql in Django 1.9. (The psycopg2 name can still be used for backwards compatibility.) Essentially, for Django ≥1.9, use django.db

问题 It seems when I use callproc(), psycopg2 isn't properly casting strings as text or character varying. For example: values = [pid, 4, 4, 'bureau ama', 0, 130, row['report_dte'], row['report_dte'], 1, 1, 1, None, None, 'published', row['report_dte']] cur.callproc('header', values) Yields: psycopg2.ProgrammingError: function header(integer, integer, integer, unknown, integer, integer, unknown, unknown, integer, integer, integer, unknown, unknown, unknown, unknown) does not exist LINE 1: SELECT *

问题 I'm trying to use a server-side curser in psycop2 as detailed in this blog post. In essence, this is achieved with from django.db import connection if connection.connection is None: cursor = connection.cursor() # This is required to populate the connection object properly cursor = connection.connection.cursor(name='gigantic_cursor') When I execute the query: cursor.execute('SELECT * FROM %s WHERE foreign_id=%s' % (table_name, id)) I get a ProgrammingError : psycopg2.ProgrammingError: can't

问题 I'm running Django 1.3 with PostgreSQL 9.1/PostGIS 1.5, psycopg2 2.4.2 and pgbouncer 1.4.2. On every single connection to the database I get a log entry in pgbouncer.log: 2011-11-20 02:15:25.027 29538 LOG S-0x96c2200: app_db/postgres@192.168.171.185:5432 closing because: unclean server (age=0). I can't find any solution to this problem - anybody have an idea why? I've tried reconfiguring pgbouncer (session/transaction mode, different timeouts etc), but to no avail. 回答1: Ok, I think I've

问题 I'm running a bunch of queries using Python and psycopg2. I create one large temporary table w/ about 2 million rows, then I get 1000 rows at a time from it by using cur.fetchmany(1000) and run more extensive queries involving those rows. The extensive queries are self-sufficient, though - once they are done, I don't need their results anymore when I move on to the next 1000. However, about 1000000 rows in, I got an exception from psycopg2: psycopg2.OperationalError: out of shared memory HINT

问题 I'd like to log the queries that psycopg2 is making, but the psycopg2 documentation doesn't really specify how LoggingConnection should be used. import logging from psycopg2.extras import LoggingConnection db_settings = { "user": "abcd", "password": "efgh", "host": "postgres.db", "database": "dev", } conn = LoggingConnection(**db_settings) Gives an error LoggingConnection(**db_settings) TypeError: function takes at most 2 arguments (5 given) 回答1: Seems like setting the connection_factory

问题 I have data coming from mongodb which looks like data = ( { u'name': 'A', u'primary_key': 1 }, { u'name': 'B', u'primary_key': 2 }, { u'name': 'C', u'primary_key': 3 } ) when I call the following cur = conn.cursor() cur.executemany("""INSERT INTO ddmension(id,name) VALUES (%(primary_key)s, %(name)s)""", data) it fails saying ProgrammingError: 'syntax error at or near """"INSERT INTO dimension (id, name) VALUES (1, E\'A\')""""\nLINE 1: """INSERT INTO dimension (id, name) VALUES (1, E\'A\n ^\n'

问题 I am having trouble getting my query to work. I have a JSON file with over 80k lines of data. Since I have been having so many problems I cut the document down to three lines just to see if I can get the data in before I attempt the full 80k lines: Import psycopg2 import io readTest1 = io.open("C:\Users\Samuel\Dropbox\Work\Python and Postgres\test1.json", encoding = "utf-8") readAll = readTest1.readlines() I have seen online that using readlines is not the best method but it is the only