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

The SQL you want is

select name from studens where id in (1, 5, 8)

If you want to construct this from the python you could use

l = [1, 5, 8]
sql_query = 'select name from studens where id in (' + ','.join(map(str, l)) + ')'

The map function will transform the list into a list of strings that can be glued together by commas using the str.join method.

Alternatively:

l = [1, 5, 8]
sql_query = 'select name from studens where id in (' + ','.join((str(n) for n in l)) + ')'

if you prefer generator expressions to the map function.

UPDATE: S. Lott mentions in the comments that the Python SQLite bindings don't support sequences. In that case, you might want

select name from studens where id = 1 or id = 5 or id = 8

Generated by

sql_query = 'select name from studens where ' + ' or '.join(('id = ' + str(n) for n in l))