返回声明不等待

Question

当执行return true 或return false 时，它不会await 那些结果并返回undefined。 但是它确实正确地执行了if 语句，只是返回true 或false 不起作用

在登录row.channelOwner 之前先登录undefined，这让我觉得它没有等待返回。

（channel为频道ID，user为用户ID）

client.on('message', async message => {
    if (!message.content.startsWith('=test') || message.author.bot) return;
    const args = message.content.slice('=test'.length).trim().split(' ');
    
    var result = await cowner(args[0],args[1])
    console.log(result)
})

cowner = async function(channel, user) {
    let query = `SELECT channelOwner FROM voice WHERE channelID = ${channel}`

    db.each(query, [], async (err, row) => {
        if (err) {
            console.log(err);
        }

        console.log(row.channelOwner)
        console.log(user) // row.channelOwner and user is the same

        // It logs reached if and reached else so the if statement is working
        if (user === row.channelOwner) {
            console.log('reached if')
            return true;
        } else {
            console.log('reached else')
            return false;
        }
    })
}

Answer 1

（原答案已删）

如果这是 SQLite3，那么使用each 来查找用户是否是频道所有者有点复杂。我建议使用db.all 甚至db.get （因为它似乎只返回零或一行，而不是更多），同时将它们包装在Promise 中，如下所示：

如果使用db.get()

cowner = async function(channel, user) {
  let query = `SELECT channelOwner FROM voice WHERE channelID = ${channel}`

  const row = await new Promise((resolve, reject) => {
    db.get(query, [], (err, row) => {
      if (err) {
        console.log(err);
        reject(err)
      }

      resolve(row)
    })
  })

  console.log(row.channelOwner)
  console.log(user) // row.channelOwner and user is the same

  // It logs reached if and reached else so the if statement is working
  if (user === row.channelOwner) {
    console.log('reached if')
    return true;
  } else {
    console.log('reached else')
    return false;
  }
}

如果使用db.all()

cowner = async function(channel, user) {
  let query = `SELECT channelOwner FROM voice WHERE channelID = ${channel}`

  const rows = await new Promise((resolve, reject) => {
    db.all(query, [], (err, rows) => {
      if (err) {
        console.log(err);
        reject(err)
      }

      resolve(rows)
    })
  })

  // Iterate through the resulting rows and check if there is one row which channelOwner matches the user
  const isChannelOwner = rows.some(row => user === row.channelOwner)

  // It logs reached if and reached else so the if statement is working
  if (isChannelOwner) {
    console.log('reached if')
    return true;
  } else {
    console.log('reached else')
    return false;
  }
}

如果您想继续使用each，请在此处阅读答案：sqlite3 - promise for asynchronous calls