Question

我正在使用Sequelize，但无法记录promise的值。我正在做console.log('helooo', timekeep);，但它会打印Promise { <pending> }。我不知道我是否做对了。

这是我的代码：

const create = async function(req, res) {
    res.setHeader('Content-Type', 'application/json');
    let err, orders, wallet;
    let orders_info = req.body;  
    console.log('order_info : <<<<<< ' + JSON.stringify(orders_info));
    var timekeep =  Orders.findAndCountAll(
    {
        where: {
          cid : orders_info.cid,
        },      
        order: [
          ['id', 'DESC']
        ],
        limit: 1,
      }
   )
   .then(result => {
       console.log('hello', result);
       console.log(result.count);
       console.log(result.rows);
   });
   console.log('helooo',  timekeep);
}

登录变量时，我会得到这样的提示。

helooo
Promise {
_bitField: 0,
_fulfillmentHandler0: undefined,
_rejectionHandler0: undefined,
_promise0: undefined,
_receiver0: undefined }

Answer 1

timekeep是您从then子句返回的值，即Promise<void>，因为它没有返回值。

使用result打印的console.log('hello', result);具有您从Promise中获得的价值。

Answer 2

我可以看到您的create函数已经是async函数。因此，不要使用Promise语法，而应使用async / await语法。现在，您正在尝试将查询表达式分配给变量timekeep。这是示例代码，

const create = async function (req, res) {
    res.setHeader('Content-Type', 'application/json');
    let err, orders, wallet;
    let orders_info = req.body;
    console.log('order_info : <<<<<< ' + JSON.stringify(orders_info));
    // try resolving promise
    try {
        var timekeep = await Orders.findAndCountAll(
            {
                where: {
                    cid: orders_info.cid,
                },
                order: [
                    ['id', 'DESC']
                ],
                limit: 1,
            }
        );
        console.log("RESULT => ", timekeep)
    } catch (err) {
        // catch error here
        console.log(err)
    }
}

Answer 3

返回数据和async await概念存在一些小问题，请在下面的代码中添加注释：

var timekeep = await Orders.findAndCountAll({ // <----------- you need add await
    where: {
        cid: orders_info.cid,
    },
    order: [
        ['id', 'DESC']
    ],
    limit: 1,
})
.then(result => {
    console.log('hello', result);
    console.log(result.count);
    console.log(result.rows);
    return result; // <----------- also need to return the result from here
});
console.log('helooo', timekeep); // <----- Now check the console

如何控制台记录诺言Sequelize的返回值

3 个答案: