How to quote a string value explicitly (Python DB API/Psycopg2)
django, psycopg2, python, sql
Solution
Ok, so I was curious and went and looked at the source of psycopg2. Turns out I didn't have to go further than the examples folder :)
And yes, this is psycopg2-specific. Basically, if you just want to quote a string you'd do this:
from psycopg2.extensions import adapt
print adapt("Hello World'; DROP DATABASE World;")
But what you probably want to do is to write and register your own adapter;
In the examples folder of psycopg2 you find the file 'myfirstrecipe.py' there is an example of how to cast and quote a specific type in a special way.
If you have objects for the stuff you want to do, you can just create an adapter that conforms to the 'IPsycopgSQLQuote' protocol (see pydocs for the myfirstrecipe.py-example...actually that's the only reference I can find to that name) that quotes your object and then registering it like so:
from psycopg2.extensions import register_adapter
register_adapter(mytype, myadapter)
Also, the other examples are interesting; esp. 'dialtone.py' and 'simple.py'.
Problem
For some reasons, I would like to do an explicit quoting of a string value (becoming a part of constructed SQL query) instead of waiting for implicit quotation performed by `cursor.execute` method on contents of its second parameter. By "implicit quotation" I mean: ``` value = "Unsafe string" query = "SELECT * FROM some_table WHERE some_char_field = %s;" cursor.execute( query, (value,) ) # value will be correctly quoted ``` I would prefer something like that: ``` value = "Unsafe string" query = "SELECT * FROM some_table WHERE some_char_field = %s;" % \ READY_TO_USE_QUOTING_FUNCTION(value) cursor.execute( query ) # value will be correctly quoted, too ``` Is such low level `READY_TO_USE_QUOTING_FUNCTION` expected by Python DB API specification (I couldn't find such functionality in PEP 249 document). If not, maybe Psycopg2 provides such function? If not, maybe Django provides such function? I would prefer not to write such function myself...