node.js 如何在猫鼬中执行 findOne 查询
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How to perform findOne query in mongoose
提问by Mohamed Challouf
i have mongoose schema named administrator
我有名为管理员的猫鼬模式
var administratorSchema = new mongoose.Schema({
username : String,
password : String,
active : Boolean,
level : String
});
When i try this query,i can get the result
当我尝试这个查询时，我可以得到结果
mongoose.connect('mongodb://'+dbServer+'/'+dbName, function(connectionError) {
var administratorModel = mongoose.model('administrators',administratorSchema);
administratorModel.findOne({_id,111155dffxv}function(err, resad){
console.log('into mongoose findone');
});
});
====> Console output : 'into mongoose findone'
The problem is : when i try to change the criteria from _id to "username", mongoose dosen't work and findOne dosen't execute:
问题是：当我尝试将标准从 _id 更改为“用户名”时，猫鼬不起作用并且 findOne 不执行：
mongoose.connect('mongodb://'+dbServer+'/'+dbName, function(connectionError) {
var administratorModel = mongoose.model('administrators',administratorSchema);
administratorModel.findOne({'username','mohamed'}function(err, resad){
console.log('into mongoose findone');
});
});
====> Console output : ''
Thanks.
谢谢。
回答by JohnnyHK
Your query object isn't valid (use a colon instead of a comma) and you're missing a comma between the findOneparameters. Your call should look like this instead:
您的查询对象无效（使用冒号而不是逗号）并且您在findOne参数之间缺少逗号。你的电话应该是这样的：
administratorModel.findOne({'username': 'mohamed'}, function(err, resad){
console.log('into mongoose findone');
});
You should also be checking the errparameter of your callbacks to see if things are working.
您还应该检查err回调的参数以查看是否正常。
Not sure why it was reaching the callback with your _idcriteria version as that one has the same issues.
不知道为什么它会使用您的_id标准版本进行回调，因为该版本具有相同的问题。
