Question

I am working with over 29 million elements, so thought a database would make more sense than an array.

Previously I was passing elements one at a time to the execute function, but I believe passing an array of 100,000 elements at a time to the executemany function would be more efficient.

I have shortened my 180 odd line code into this short test-case:

import sqlite3

if __name__ == '__main__':
    connection = sqlite3.connect('array.db')
    cursor = connection.cursor()
    cursor.execute("create table array (word text);")
    cursor.executemany("insert into array values (?)", [u'usa', u'sharp', u'rise', u'seen', u'in', u'cd', u'bootlegs', u'sharp', u'rise', u'seen', u'in', u'cd', u'bootlegs', u'los', u'angeles'])
    connection.commit()
    cursor.execute("select * from array;")
    print cursor.fetchall()

Output:

Traceback (most recent call last):
        cursor.executemany("insert into array values (?)", [u'usa', u'sharp', u'rise', u'seen', u'in', u'cd', u'bootlegs', u'sharp', u'rise', u'seen', u'in', u'cd', u'bootlegs', u'los', u'angeles'])
    sqlite3.ProgrammingError: Incorrect number of bindings supplied. The current statement uses 1, and there are 3 supplied.

What am I doing wrong?

Answer 1

Ahh, they need to be in their own elements:

import sqlite3

if __name__ == '__main__':
    connection = sqlite3.connect('array.db')
    cursor = connection.cursor()
    cursor.execute("create table array (word text);")
    cursor.executemany("insert into array values (?)", [[u'nabisco'],[u'usa'], [u'sharp'], [u'rise']])
    connection.commit()
    cursor.execute("select * from array;")
    print cursor.fetchall()