在express中的每个数组元素中进行猫鼬查询时如何处理异步？

Posted 2023-03-11

【中文标题】在express中的每个数组元素中进行猫鼬查询时如何处理异步？

【英文标题】：How to handle async when making mongoose query in each array element in express?

【发布时间】：2020-09-12 17:06:16

【问题描述】：

在以下发布方法中，由于月光异步，我遇到了一些问题。先执行res.send(suggestions)，然后执行Expense.findOne.exec

app.post('/suggestions', async function(req, res) 
    const suggestions = await req.body.map((description) => 
        Expense.findOne( description: new RegExp(description, 'i') ).exec((err, result) => 
            if (result) 
                console.log(result.newDescription);
                return 
                    description,
                    newDescription: result.newDescription,
                    category: result.category,
                    subcategory: result.subcategory
                ;
            
        );
    );

    res.send(suggestions);
);

结果是一个空值数组。如何对每个项目执行查询，然后执行res.send(suggestion)？

【参考方案1】：

使用以下代码找到解决方案：

app.post('/suggestions', async function(req, res) 
    try 
        if (req.body.length > 0) 
            const suggestions = req.body.map((description) =>
                Expense.findOne( description: new RegExp(description, 'i') )
            );

            const results = await Promise.all(suggestions);
            return res.send(results);
        
     catch (e) 
        console.log('error', e);
    
);