[英]Remove multiple records from a collection- MongoDB
I have two models with the following schemas: 我有两个具有以下架构的模型:
Map: 地图:
var MapSchema = mongoose.Schema({
ownerId:{
type: Schema.Types.ObjectId,
ref: 'User',
required: true
},
mapName: {
type: String
},
mapImagePath:{
type: String,
required: true
},
createdAt: { type: Date, default: Date.now },
devices: [{type: Schema.Types.ObjectId, ref: 'Device'}]
});
Device: 设备:
var DeviceSchema = mongoose.Schema({
deviceName:{
type: String,
required: true,
index: true,
unique: true
},
roomCapacity: {
type: Number
},
roomImagePath:{
type: String,
},
mapId:{
type: Schema.Types.ObjectId,
ref: 'Map',
required: true
},
coords:{
type: [Number], //[xcoord, ycoord]
required: true
},
status:{
type: String,
required: true,
default: 'Available'
},
user:{
type: String,
},
createdAt: { type: Date, default: Date.now }
});
As you can see, one map has many devices. 如您所见,一张地图有很多设备。 Now, When I delete a map, I want to delete all of the devices that belong to it.
现在,当我删除地图时,我想删除属于它的所有设备。 This should be easy because each map has an array of it's device ID's.
这应该很容易,因为每个地图都有其设备ID的数组。 But I can not seem to find a way to delete multiple records from a collection at once.
但是我似乎找不到一种立即从集合中删除多个记录的方法。 I delete my map with this function:
我使用以下功能删除地图:
module.exports.deleteMap = function(mapId, callback){
Map.findOneAndRemove({_id: mapId}, callback)
};
This returns the map so I can access it's device ID's as map.devices. 这将返回地图,因此我可以将其设备ID作为map.devices进行访问。 However, how can I now use map.devices to remove all of these from the device collection?
但是,现在如何使用map.devices从设备集合中删除所有这些? I was thinking something like device.remove(map.devices) ?
我在想类似device.remove(map.devices)的东西吗?
You can first find the map object and use the array of device _id
s with the $in
operator to remove all the devices in the map. 您可以首先找到地图对象,并使用
$in
_运算符使用device _id
数组来删除地图中的所有设备。 Below is some (untested) sample code. 以下是一些(未经测试的)示例代码。
module.exports.deleteMap = function(mapId, callback) {
Map.findOneAndRemove({_id: mapId}, function(dbErr, map) {
if(dbErr) {
return callback(dbErr);
}
Device.remove({_id: {$in: map.devices}}, function(dbErr) {
if(dbErr) {
return callback(dbErr);
}
return callback(undefined, map);
});
});
};
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.