Question

我的两个变量“ soundTypeFound [0] .name”和“ req.soundTypes [iteration]”每次都必须相同，但五倍于其为假。

我认为循环比函数“ allSoundTypeQuery.GetSoundTypeByName（item，（soundTypeFound，err）=> {}”）更快，并且变量“ iteration”没有与循环相同的时间递增

谢谢您的帮助

async function checkSoundTypes (req, res, soundTypesString, error, next) {
    let stop = false;
    req.soundTypes = soundTypesString.split(',');

    let iteration = 0;
    for (let item of req.soundTypes) {

      await allSoundTypeQuery.GetSoundTypeByName(item, (soundTypeFound, err) => {
            if (err) {
                return res.status(500).json({"error": "Cannot find the sound type in the DB"});
            }

            if (soundTypeFound.length <= 0 || soundTypeFound[0].name !== req.soundTypes[iteration]) {
                stop = true;
            }
            iteration++;
            if (iteration === req.soundTypes.length) {
                if (stop === true) {
                    error.push("soundTypes");
                    return res.status(400).json(error);
                }else if (err) {
                    return res.status(400).json(error);
                }else {
                    next();
                }
            }
        });
    }
}

Answer 1

由于您正在发送回调函数，它将不会等待并继续进行下一次迭代，因此会导致错误，现在该方法将返回promise，因为我们正在使用util模块的promisify方法，而不是等待解决的诺言，然后转到下一行。

const {promisify} = require('util');

async function checkSoundTypes (req, res, soundTypesString, error, next) {
let stop = false;
req.soundTypes = soundTypesString.split(',');

let iteration = 0;
for (let item of req.soundTypes) {
    const getSoundTypeByName = promisify(allSoundTypeQuery.GetSoundTypeByName);
    const soundTypeFound= await getSoundTypeByName(item);
    if (!soundTypeFound) { // this you should check as per your response
        return res.status(500).json({"error": "Cannot find the sound type in the DB"});
    }

    if (soundTypeFound.length <= 0 || soundTypeFound[0].name !== req.soundTypes[iteration]) {
        stop = true;
    }
    iteration++;
    if (iteration === req.soundTypes.length) {
        if (stop === true) {
            error.push("soundTypes");
            return res.status(400).json(error);
        }else if (err) {
            return res.status(400).json(error);
        }else {
            next();
        }
    }
}

}

我的两个变量有时不相等，但必须是

1 个答案: