getting ids of multiple rows inserted in psycopg2

Question

I\'d like to use psycopg2 to INSERT multiple rows and then return all the ids (in order) using a single query. This is what PostgreSQL\'s RET

Answer 1

The trick is to use mogrify. It uses a single execute and id therefore faster than executemany anyways:

def insert_many(self, table: str, id_column: str, values: list):
    if not values:
        return []

    keys = values[0].keys()
    query = cursor.mogrify("INSERT INTO {} ({}) VALUES {} RETURNING {}".format(
            table,
            ', '.join(keys),
            ', '.join(['%s'] * len(values)),
            id_column
        ), [tuple(v.values()) for v in values])

    conn = psycopg2.connect("host=localhost4 port=5432 dbname=cpn")
    cursor = conn.cursor()
    cursor.execute(query)
    return [t[0] for t in (cursor.fetchall()]