Retrieves data (D) and names (N) from relational tables.

def readTables(self):
        """Retrieves data (D) and names (N) from relational tables.
        """
        class D: pass
        cur=self.cur
        cur.execute('SELECT * FROM users')
        D.users = cur.fetchall()
        cur.execute('SELECT * FROM profiles')
        D.profiles = cur.fetchall()
        cur.execute('SELECT * FROM articles')
        D.articles = cur.fetchall()
        cur.execute('SELECT * FROM comments')
        D.comments = cur.fetchall()
        cur.execute('SELECT * FROM friendships')
        D.friendships= cur.fetchall()
        cur.execute('SELECT * FROM votes')
        D.votes= cur.fetchall()
        cur.execute('SELECT * FROM tags')
        D.tags= cur.fetchall()
        cur.execute('SELECT * FROM taggings')
        D.taggings= cur.fetchall()
        self.D=D

        class N: pass
        cur.execute("select column_name from information_schema.columns where table_name='users';")
        UN=cur.fetchall()
        N.UN=[i[0] for i in UN[::-1]]
        cur.execute("select column_name from information_schema.columns where table_name='profiles';")
        PN=cur.fetchall()
        N.PN=[i[0] for i in PN[::-1]]
        cur.execute("select column_name from information_schema.columns where table_name='articles';")
        AN=cur.fetchall()
        N.AN=[i[0] for i in AN[::-1]]
        cur.execute("select column_name from information_schema.columns where table_name='comments';")
        CN=cur.fetchall()
        N.CN=[i[0] for i in CN[::-1]]
        cur.execute("select column_name from information_schema.columns where table_name='friendships';")
        FRN=cur.fetchall()
        N.FRN=[i[0] for i in FRN[::-1]]
        cur.execute("select column_name from information_schema.columns where table_name='votes';")
        VN=cur.fetchall()
        N.VN=[i[0] for i in VN[::-1]]
        cur.execute("select column_name from information_schema.columns where table_name='tags';")
        TN=cur.fetchall()
        N.TN=[i[0] for i in TN[::-1]]
        cur.execute("select column_name from information_schema.columns where table_name='taggings';")
        TTN=cur.fetchall()
        N.TTN=[i[0] for i in TTN[::-1]]
        self.N=N