我如何使用Mongo功能对这些数据进行排序:
输入
{ "_id" : 1, "domainName" : "test1.com", "hosting" : "hostgator.com" }
{ "_id" : 2, "domainName" : "test2.com", "hosting" : "aws.amazon.com"}
{ "_id" : 3, "domainName" : "test3.com", "hosting" : "aws.amazon.com" }
{ "_id" : 4, "domainName" : "test4.com", "hosting" : "hostgator.com" }
{ "_id" : 5, "domainName" : "test5.com", "hosting" : "aws.amazon.com" }
{ "_id" : 6, "domainName" : "test6.com", "hosting" : "cloud.google.com" }
{ "_id" : 7, "domainName" : "test7.com", "hosting" : "aws.amazon.com" }
{ "_id" : 8, "domainName" : "test8.com", "hosting" : "hostgator.com" }
{ "_id" : 9, "domainName" : "test9.com", "hosting" : "cloud.google.com" }
{ "_id" : 10, "domainName" : "test10.com", "hosting" : "godaddy.com" }
为了按托管字段排序,要获得结果,例如按以下顺序:
1)首先-所有哥达;
2)其次-所有AWS
3)接下来,其他所有内容。
输出
{
"result" : [
{
"_id" : 10,
"domainName" : "test10.com",
"hosting" : "godaddy.com"
},
{
"_id" : 2,
"domainName" : "test2.com",
"hosting" : "aws.amazon.com"
},
{
"_id" : 3,
"domainName" : "test3.com",
"hosting" : "aws.amazon.com"
},
{
"_id" : 5,
"domainName" : "test5.com",
"hosting" : "aws.amazon.com"
},
{
"_id" : 7,
"domainName" : "test7.com",
"hosting" : "aws.amazon.com"
},
{
"_id" : 1,
"domainName" : "test1.com",
"hosting" : "hostgator.com"
},
{
"_id" : 4,
"domainName" : "test4.com",
"hosting" : "hostgator.com"
},
{
"_id" : 6,
"domainName" : "test6.com",
"hosting" : "cloud.google.com"
},
{
"_id" : 8,
"domainName" : "test8.com",
"hosting" : "hostgator.com"
},
{
"_id" : 9,
"domainName" : "test9.com",
"hosting" : "cloud.google.com"
},
]
}
在此示例中,我想以更相关的方式为用户返回结果。在origanl任务中,我想使用其他几个收集的其他信息进行排序,这些收集可以提供其他信息。
但是,如果您可以帮助我完成上一个任务,那就足够了吗?
UPD:关于问题的第二部分。
另一个任务是如何根据另一个集合从一个集合返回可排序的数据。
例子:
第一个集合与之前给出的相同:
{ "_id" : 1, "domainName" : "test1.com", "hosting" : "hostgator.com" }
...
第二个集合,提供有关托管的其他信息:
{ '_id': 123, 'quality':'best', 'hostings': ["hostgator.com", "aws.amazon.com"]},
{ '_id': 321, 'quality':'good', 'hostings': ["cloud.google.com"]},
{ '_id': 345, 'quality':'bad', 'hostings': ["godaddy.com"]},
结果,我需要按以下顺序从第一个集合数据中返回:
1)首先,所有主机都不错2)其次,所有主机都不错3)第三,所有主机都不好
输出:
{
"result" : [
//Best:
{
"_id" : 1,
"domainName" : "test1.com",
"hosting" : "hostgator.com"
},
{
"_id" : 4,
"domainName" : "test4.com",
"hosting" : "hostgator.com"
},
{
"_id" : 8,
"domainName" : "test8.com",
"hosting" : "hostgator.com"
},
{
"_id" : 2,
"domainName" : "test2.com",
"hosting" : "aws.amazon.com"
},
{
"_id" : 3,
"domainName" : "test3.com",
"hosting" : "aws.amazon.com"
},
{
"_id" : 5,
"domainName" : "test5.com",
"hosting" : "aws.amazon.com"
},
{
"_id" : 7,
"domainName" : "test7.com",
"hosting" : "aws.amazon.com"
},
// Good:
{
"_id" : 9,
"domainName" : "test9.com",
"hosting" : "cloud.google.com"
},
{
"_id" : 6,
"domainName" : "test6.com",
"hosting" : "cloud.google.com"
},
//Bad
{
"_id" : 10,
"domainName" : "test10.com",
"hosting" : "godaddy.com"
}
]
}
更新2
我在前面的示例中得到了很好的答案和示例。非常感谢!但是我举了另一个例子。
我需要比较3个集合的ID进行排序-第一个:朋友,第二个:“请求”,以及:其他用户。
输入
db.friends.find({userId: currentUser});
// {"_id" : "PgC7LrtaZtQsShtzT", "userId" : "tHuxnWxFLHvcpRgHb", "friendId" : "jZagPF7bd4aW8agXb",}
db.requests.find({userId: currentUser});
// looks like friend but with 'requesterId'
现在,我需要汇总“用户”集合,定义与前两个集合(朋友,请求)相匹配的分数。
使用提供的答案,我管理结果,但仅收集了一个。如何用3个或多个做这个?
您可以将每个hosting
in投影到由整数表示的单独类型中,最后对这些整数进行排序。在下面的聚合管道中进行了说明
[
{$lookup: {
from: 'secondCollectionStoringQuality',
localField: 'hosting',
foreignField: 'hostings',
as: 'nw'
}},
{$unwind: '$nw'},
{$project: {
domainName: 1,
hosting: 1,
type: {
$cond: [
{$eq: ['$nw.quality', 'best']},
0,
{$cond: [
{$eq: ['$nw.quality', 'good']},
1,
2
]}
]
}
}},
{$sort: {type: 1}}
]
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