using sqlite3 database for flaskr in python without ORM
<p>Im trying to use sqlite3 for my python project. I need to make a register page to register users for accessing other features. so I need to check if the username or email exists or not . and I have been forbidden using ORM (sorry for my bad English ).the only tutorial that I have passed is this :<a href="http://flask.pocoo.org/docs/0.10/tutorial/introduction/" rel="nofollow">http://flask.pocoo.org/docs/0.10/tutorial/introduction/</a>
but I dont know how to work with database,how to get table information and cells and ... 
can you please tell me how or give me a reference?
I think I must know some commands like this :</p>

<pre><code>@app.route('/')
def show_entries():
    #specially this line
    cur = g.db.execute('select title, text from entries order by id desc')
    entries = [dict(title=row[0], text=row[1]) for row in cur.fetchall()]
    return render_template('show_entries.html', entries=entries)
</code></pre>