Question

我最近是一名PHP程序员，为了使一个项目完成，我已经惊讶地使用nodejs了，不幸的是，还可以使用dynamo db，所以在这里我遇到了一个问题，我知道这可能是基本的如此愚蠢

正在执行的代码在这里

  if (typeof(req.body.question) == 'object') {
          quest = req.body.question;
        }
        if (typeof(req.body.question) == 'string') {
          quest = req.body.question;
        }else{
          questionsq = {
            'ConsistentRead': true,
            TableName : 'testquestions',
            KeyConditionExpression: "testid = :testid",
            ExpressionAttributeValues: { ":testid":{'S':'f3b21bf0-d6b9-11e8-bdf1-f7fcc44e7f9c'} }
          };
          vulog.info('Question is not settled so querying',questionsq);
          dynamodb.query(questionsq, function(err,quest){
              vulog.info('The data:',JSON.stringify(quest));
              if(err || !quest ){
                  vulog.error('Query went wrong',err);
              }else{
                vulog.info('Query went fine',JSON.stringify(quest));
                //return quest;
              }
          });
        }

在此之后，我希望这段代码能够正常工作。

var originalQuestions = [];
vulog.debug('--------------------');
if (!quest || quest.length == 0) {
  vulog.warn('Questions not entered');
  errstr += '\nAt least one interview question must be entered';
} else {
 //Goes on

目前，我正在终端中接收该消息，并且卡在了那里，没有进一步执行。

Query went fine {"Items":[{//Datas}],"Count":2,"ScannedCount":2}

我要的是我要执行代码的第一部分并给出quest的值，然后继续执行代码。我该怎么办现在它正在执行并卡在那 vulog.info（'查询很好'，JSON.stringify（quest））;没有进一步的处决：）

Answer 1

编辑：

异步/等待方法：

async function() {
  ........
  var quest = await queryQuestion();
  var originalQuestions = [];
  vulog.debug('--------------------');
  if (!quest || quest.length == 0) {
    vulog.warn('Questions not entered');
    errstr += '\nAt least one interview question must be entered';
  } else {
    //Goes on
  }
}

原始答案：

您可以将第一个逻辑包装在函数中，然后返回一个Promise，然后将resolve转换为quest或reject和error

function queryQuestion() {
return new Promise(function(resolve, reject) {
    if (typeof(req.body.question) == 'object' || typeof(req.body.question) == 'string') {
        quest = req.body.question;
      	resolve(quest);
    } else {
        questionsq = {
            'ConsistentRead': true,
            TableName: 'testquestions',
            KeyConditionExpression: "testid = :testid",
            ExpressionAttributeValues: {
                ":testid": {
                    'S': 'f3b21bf0-d6b9-11e8-bdf1-f7fcc44e7f9c'
                }
            }
        };
        vulog.info('Question is not settled so querying', questionsq);
        dynamodb.query(questionsq, function(err, quest) {
            vulog.info('The data:', JSON.stringify(quest));
            if (err || !quest) {
                vulog.error('Query went wrong', err);
                reject(error);
            } else {
                vulog.info('Query went fine', JSON.stringify(quest));
                //return quest;
                resolve(quest);
            }
        });
    }
})
}

然后调用此函数

queryQuestion().then(function(quest){
  var originalQuestions = [];
  vulog.debug('--------------------');
  if (!quest || quest.length == 0) {
    vulog.warn('Questions not entered');
    errstr += '\nAt least one interview question must be entered';
  } else {
    //Goes on
  }
}, function(error){
  // Handle errors
})

希望这对您有所帮助。

如何从nodejs代码执行中获取带有db值的结果？

1 个答案: