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pythonpostgresqlpsycopg2

Create a Postgres database using python


I want to create Postgres database using Python.

con = psql.connect(dbname='postgres',
      user=self.user_name, host='',
      password=self.password)

cur = con.cursor()
cur.execute("CREATE DATABASE %s  ;" % self.db_name)

I am getting the following error:

InternalError: CREATE DATABASE cannot run inside a transaction block

I am using psycopg2 to connect. I don't understand what's the problem. What am I trying to do is to connect to database (Postgres):

psql -postgres -U UserName

And then create another database:

create database test;

This is what I usually do and I want to automate this by creating Python script.


Solution

  • Use ISOLATION_LEVEL_AUTOCOMMIT, a psycopg2 extensions:

    No transaction is started when command are issued and no commit() or rollback() is required.

    import psycopg2
    from psycopg2 import sql
    from psycopg2.extensions import ISOLATION_LEVEL_AUTOCOMMIT # <-- ADD THIS LINE
    
    con = psycopg2.connect(dbname='postgres',
          user=self.user_name, host='',
          password=self.password)
    
    con.set_isolation_level(ISOLATION_LEVEL_AUTOCOMMIT) # <-- ADD THIS LINE
    
    cur = con.cursor()
    
    # Use the psycopg2.sql module instead of string concatenation 
    # in order to avoid sql injection attacks.
    cur.execute(sql.SQL("CREATE DATABASE {}").format(
            sql.Identifier(self.db_name))
        )