Mongodb 在$unwind之前检查子文档是否为空
我有一个工作模式,其中包含职位、工作地点、工资等 ApplicationSchema将子文档嵌入到作业文档中,并存储此特定作业收到的所有应用程序 以下是作业模式的外观Mongodb 在$unwind之前检查子文档是否为空,mongodb,mongodb-query,aggregation-framework,Mongodb,Mongodb Query,Aggregation Framework,我有一个工作模式,其中包含职位、工作地点、工资等 ApplicationSchema将子文档嵌入到作业文档中,并存储此特定作业收到的所有应用程序 以下是作业模式的外观 const jobSchema = new Schema({ job_title : { type : String, required : true }, job_location : { type : String, }, salary : { type : Number
const jobSchema = new Schema({
job_title : {
type : String,
required : true
},
job_location : {
type : String,
},
salary : {
type : Number
},
applications: [ApplicationSchema],
companyId : {
type: mongoose.Schema.Types.ObjectId,
ref: 'Company'
}
},{timestamps : true});
var Job = mongoose.model('Job', jobSchema);
module.exports = Job;
您可以看到上面的应用程序子文档
下面是我的工作文档在没有特定工作申请时的外观
{
"_id" : ObjectId("5ac873c3bb7a9c3168ff159e"),
"applications" : [],
"job_title" : "Junior Developer",
"companyId" : ObjectId("5ac870d0bb7a9c3168ff159c"),
"createdAt" : ISODate("2018-04-07T07:31:15.257Z"),
"updatedAt" : ISODate("2018-04-07T09:20:52.237Z"),
"__v" : 2,
"job_location" : "Pune, Maharashtra, India",
"salary" : 3
}
和应用程序
{
"_id" : ObjectId("5ac873c3bb7a9c3168ff159e"),
"applications" : [
{
"applied" : true,
"shortlisted" : false,
"interviewed" : false,
"offered" : false,
"hired" : false,
"rejected" : false,
"rejectedComment" : ""
},
{
"applied" : true,
"shortlisted" : false,
"interviewed" : false,
"offered" : false,
"hired" : false,
"rejected" : false,
"rejectedComment" : ""
}
],
"job_title" : "Junior Developer",
"companyId" : ObjectId("5ac870d0bb7a9c3168ff159c"),
"createdAt" : ISODate("2018-04-07T07:31:15.257Z"),
"updatedAt" : ISODate("2018-04-07T09:20:52.237Z"),
"__v" : 2,
"job_location" : "Pune, Maharashtra, India",
"salary" : 3
}
这里是查询
var jobsQuery = [
{
$match: {
companyId: mongoose.Types.ObjectId(req.body.companyId),
active: req.body.active
}
},
{
$unwind: "$applications"
},
{
$match : query
},
{
"$group":
{
"_id": "$job_title",
"job_title": {$first: "$_id"},
"job_location": {$first: "$job_location"},
"min_experience": {$first: "$min_experience"},
"max_experience": {$first: "$max_experience"},
"min_salary": {$first: "$min_salary"},
"max_salary": {$first: "$max_salary"},
"createdAt": {$first: "$createdAt"},
"userId": {$first: "$userId"},
"applied": {"$sum":
{"$cond":
[{"$and": [
{"$eq":["$applications.applied", true]},
{"$eq":["$applications.shortlisted", false]},
{"$eq":["$applications.interviewed", false]},
{"$eq":["$applications.offered", false]},
{"$eq":["$applications.hired", false]},
{"$eq":["$applications.rejected", false]},
]},
1,0]
}
},
}
},
{
"$lookup":
{
from: "users",
localField: "userId",
foreignField: "_id",
as: "userDetail"
}
},
]
当一份工作收到申请时,它工作得非常好,但当它没有收到申请时,它就不能放松,而这就是我一无所获的原因
那么,我怎样才能给出一些条件,使这个查询在有或没有任何应用程序的情况下都能工作呢
{
"_id" : ObjectId("5ac873c3bb7a9c3168ff159e"),
"applications" : [
{
"applied" : true,
"shortlisted" : false,
"interviewed" : false,
"offered" : false,
"hired" : false,
"rejected" : false,
"rejectedComment" : ""
},
{
"applied" : true,
"shortlisted" : false,
"interviewed" : false,
"offered" : false,
"hired" : false,
"rejected" : false,
"rejectedComment" : ""
}
],
"job_title" : "Junior Developer",
"companyId" : ObjectId("5ac870d0bb7a9c3168ff159c"),
"createdAt" : ISODate("2018-04-07T07:31:15.257Z"),
"updatedAt" : ISODate("2018-04-07T09:20:52.237Z"),
"__v" : 2,
"job_location" : "Pune, Maharashtra, India",
"salary" : 3
}
我还在申请阶段查询计数申请者,我还有其他阶段。您需要在
$unwind
操作中添加preserveNullAndEmptyArrays
属性,如下所示:
{
$unwind:
{
path: "$applications",
preserveNullAndEmptyArrays: true
}
}
如果为true,则如果路径为null、缺少或为空数组,$unwind将输出文档。如果为false,则如果路径为null、缺少或为空数组,则$unwind不会输出文档
在$match阶段,您需要$exists和$ne操作符 你的$match阶段看起来像
{
$match: {
companyId: mongoose.Types.ObjectId(req.body.companyId),
active: req.body.active,
applications:{$exists:true,$ne:[]}
}
}
您的整个管道将如下所示
[
{
$match: {
companyId: mongoose.Types.ObjectId(req.body.companyId),
active: req.body.active,
applications:{$exists:true,$ne:[]}
}
},
{
$unwind: "$applications"
},
{
$match : query
},
{
"$group":
{
"_id": "$job_title",
"job_title": {$first: "$_id"},
"job_location": {$first: "$job_location"},
"min_experience": {$first: "$min_experience"},
"max_experience": {$first: "$max_experience"},
"min_salary": {$first: "$min_salary"},
"max_salary": {$first: "$max_salary"},
"createdAt": {$first: "$createdAt"},
"userId": {$first: "$userId"},
"applied": {"$sum":
{"$cond":
[{"$and": [
{"$eq":["$applications.applied", true]},
{"$eq":["$applications.shortlisted", false]},
{"$eq":["$applications.interviewed", false]},
{"$eq":["$applications.offered", false]},
{"$eq":["$applications.hired", false]},
{"$eq":["$applications.rejected", false]},
]},
1,0]
}
},
}
},
{
"$lookup":
{
from: "users",
localField: "userId",
foreignField: "_id",
as: "userDetail"
}
},
]
更多
您好,如果找不到大于0的应用程序数组,它将立即停止。即使在发现应用程序数组为0之后,它也不应该停止。谢谢你帮我解决了完全相同的问题。