python - execute a sql script file from cx_oracle?

Question

Is there a way to execute a sql script file using cx_oracle in python.

I need to execute my create table scripts in sql files.

Answer 1

Another option is to use SQL*Plus (Oracle's command line tool) to run the script. You can call this from Python using the subprocess module - there's a good walkthrough here: http://moizmuhammad.wordpress.com/2012/01/31/run-oracle-commands-from-python-via-sql-plus/.

For a script like tables.sql (note the deliberate error):

CREATE TABLE foo ( x INT );

CREATE TABLER bar ( y INT );

You can use a function like the following:

from subprocess import Popen, PIPE

def run_sql_script(connstr, filename):
    sqlplus = Popen(['sqlplus','-S', connstr], stdin=PIPE, stdout=PIPE, stderr=PIPE)
    sqlplus.stdin.write('@'+filename)
    return sqlplus.communicate()

connstr is the same connection string used for cx_Oracle. filename is the full path to the script (e.g. 'C:empables.sql'). The function opens a SQLPlus session (with '-S' to silence its welcome message), then queues "@filename" to send to it - this will tell SQLPlus to run the script.

sqlplus.communicate sends the command to stdin, waits for the SQL*Plus session to terminate, then returns (stdout, stderr) as a tuple. Calling this function with tables.sql above will give the following output:

>>> output, error = run_sql_script(connstr, r'C:empables.sql')
>>> print output

Table created.

CREATE TABLER bar (
       *
ERROR at line 1:
ORA-00901: invalid CREATE command

>>> print error

This will take a little parsing, depending on what you want to return to the rest of your program - you could show the whole output to the user if it's interactive, or scan for the word "ERROR" if you just want to check whether it ran OK.