获取多行的问题

如何解决获取多行的问题

嗨，我要从 psycopg2 转移到 asyncpg，在这种情况下，我在尝试返回 asyncpg 中的多行时遇到了问题 10。在 psycopg2 中，我将通过以下方式执行此操作：

psycopg2

cursor.execute(f"SELECT user_id,lvl,xp,total_xp FROM levels WHERE guild_id = {str(701547632666525246)} ORDER BY GREATEST(total_xp) DESC")
        res = cursor.fetchmany(10)

asycpg

res = await conn.fetch("SELECT user_id,total_xp FROM levels WHERE guild_id = $1 ORDER BY GREATEST(total_xp) DESC",ctx.guild.id)

我对 asyncpg 部分有点困惑，不胜感激。

这是我正在使用的：

@commands.command()
async def ranking(self,ctx):
    """displays top 10 Active Members in the server"""
    if ctx.message.channel.name == "commands":
        async with self.bot.pool.acquire() as conn:
            res = await conn.fetch("SELECT user_id,ctx.guild.id)
            #0: user_id,1: lvl
            mess = "Top 10 active members"
            x = 1
            for ele in res:
                user = self.bot.get_user(int(ele[0]))
                mess += "**{}.** {} on **Level {: <3}** with **{: <4} XP**\n\n".format(x,user.name,ele[1],ele[2])
                x+=1
            embed = discord.Embed(title="leaderboard",description=f"{mess}")
            await ctx.send(embed=embed)
    else:
        await ctx.send("Can't use this command in this channel.")

解决方法

您可以简单地使用 LIMIT 子句

query = """
    SELECT user_id,lvl,xp,total_xp 
    FROM levels 
    WHERE guild_id = $1 
    ORDER BY GREATEST(total_xp) DESC
    LIMIT 10
"""
await conn.fetch(query,ctx.guild.id)

它适用于 psycopg2 和 asyncpg