python list in sql query as parameter

Question

I have a python list, say l

l = [1,5,8]

I want to write a sql query to get the data for all the elements of the list, say

s         


        

Answer 1

If you're using PostgreSQL with the Psycopg2 library you can let its tuple adaption do all the escaping and string interpolation for you, e.g:

ids = [1,2,3]
cur.execute(
  "SELECT * FROM foo WHERE id IN %s",
  [tuple(ids)])

i.e. just make sure that you're passing the IN parameter as a tuple. if it's a list you can use the = ANY array syntax:

cur.execute(
  "SELECT * FROM foo WHERE id = ANY (%s)",
  [list(ids)])

note that these both will get turned into the same query plan so you should just use whichever is easier. e.g. if your list comes in a tuple use the former, if they're stored in a list use the latter.