Check if row exists in SQLite with Python

I want to know if a row exists already in one of my tables, in this case coll. In order to do this I played around with SQLite in the shell a little and stumbled upon SELECT EXISTS(SELECT 1 FROM coll WHERE ceeb="1234"). In SQLite this works perfectly and it returns either a 0 or a 1-- which is exactly what I wanted. So, with code in hand, I wrote up a quick Python script to see if I could get this to work for me before sticking it into my program. This is what I came up with:

import sqlite3
conn = sqlite3.connect('stu.db')
c = conn.cursor()
sceeb = int(raw_input(":> "))
ceeb_exists = c.execute('SELECT EXISTS(SELECT 1 FROM coll WHERE ceeb="%d" LIMIT 1)' % sceeb)
print ceeb_exists

Instead of assigning ceeb_existsa 1 or a 0 it gives me an output that looks like <sqlite3.Cursor object at 0x01DF6860>. What am I doing wrong here?

2 Answers

The execution of a query always results in 0 or more rows. You'd need to fetch those rows; a SELECT EXISTS query results in 1 row, so you'd need to fetch that row.

Rows always consist of 1 or more columns, here you get one, so you could use tuple assignment (note the , comma after ceeb_exists):

c.execute('SELECT EXISTS(SELECT 1 FROM coll WHERE ceeb="%d" LIMIT 1)' % sceeb)
ceeb_exists, = c.fetchone()

However, using an EXISTS query is a bit redundant here; you could just test if there is any row returned. You should also use query parameters to avoid a SQL injection attack (you are asking a user to give you the ceeb value, so that is easily hijacked):

c.execute('SELECT 1 FROM coll WHERE ceeb=? LIMIT 1', (sceeb,))
ceeb_exists = c.fetchone() is not None

cursor.fetchone() returns None if there is no row available to fetch, the is not None test turns that into True or False.

.executes() returns a cursor object as you can see. In order to print the results of the query you need to iterate over it:

for result in exists: print result