SQLite NULL with discord.py

Question

I have problem with my SQLITE. My lvlexp and messages are NULL
I want that messages = 0 and lvlexp = 100 with this Code I have NULL

    @commands.Cog.listener()
    async def on_message(self, message):

        if message.author.bot:
            return
        author = message.author
        guild = message.guild
        async with aiosqlite.connect('level.db') as db:
            async with db.cursor() as cursor:
                await cursor.execute("SELECT xp FROM levels WHERE user = ? AND guild = ?", (author.id,guild.id,))
                xp = await cursor.fetchone()
                await cursor.execute("SELECT level FROM levels WHERE user = ? AND guild = ?", (author.id,guild.id,))
                level = await cursor.fetchone()

                if not xp or not level:
                    await cursor.execute("INSERT INTO levels (level,xp,user,guild) VALUES (?, ?, ?, ?)", (0, 0, author.id,guild.id,))
                    await db.commit()

                await cursor.execute("SELECT lvlexp FROM levels WHERE user = ? AND guild = ?", (author.id,guild.id,))
                lvlexp = await cursor.fetchone()

                await cursor.execute("SELECT messages FROM levels WHERE user = ? AND guild = ?", (author.id,guild.id,))
                messages = await cursor.fetchone()
                if not lvlexp:
                    await cursor.execute("INSERT INTO levels (lvlexp,messages) VALUES (?, ?)", (100,0,))
                    await db.commit()