[英]Typer Error: Cannot read property 'length' of undefined
I'm creating a node.js app and implementing the scheduler app. 我正在创建一个node.js应用程序并实现调度程序应用程序。 I'm following this walkthrough: https://dhtmlx.com/blog/using-dhtmlxscheduler-with-node-js/
我正在按照以下演练进行操作: https : //dhtmlx.com/blog/using-dhtmlxscheduler-with-node-js/
When I navigate to the /data page, it says cannot read property 'length' of undefined. 当我导航到/ data页面时,它说无法读取未定义的属性“ length”。 I went to the github page and downloaded app.js word for word.
我去了github页面并逐字下载了app.js。
Here is app.js portion throwing error: 这是app.js部分抛出错误:
app.get('/data', function(req, res){
db.event.find().toArray(function(err, data){
//set id property for all records
for (var i = 0; i < data.length; i++)
data[i].id = data[i]._id;
//output response
res.send(data);
});
});
This example works fine. 这个例子很好用。 I guess, in your case,
mongoskin
fails to connect to mongodb for some reasons. 我猜,就您而言,由于某些原因,
mongoskin
无法连接到mongodb。 If I change some parts in this path mongodb://localhost/testdb
(for testing purpose, put some random string) , mongodb
will complain about problem with url
, and I'll get an error TypeError: Cannot read property 'length' of undefined
from node js, because there will be no data fetched from database. 如果我在此路径中更改了某些部分
mongodb://localhost/testdb
(出于测试目的,请放置一些随机字符串),则mongodb
将抱怨url
问题,并且我将收到错误TypeError: Cannot read property 'length' of undefined
从节点js中TypeError: Cannot read property 'length' of undefined
,因为将不会从数据库中获取任何数据。
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