英文:
How can I group data while fetching from mongodb using go?
问题
我有一个名为"myplace"的集合，它有以下字段：place_name（地点名称）、city（城市）、latitude（纬度）、longitude（经度）。
文档格式如下：
{
"_id" : ObjectId("544a2147785b707b340ed6c7"),
"latitude" : 12.36547,
"longitude" : 1.235689,
"place_name" : "some_place",
"city" : "City1"
}
{
"_id" : ObjectId("544a2147785b707b340ed6c7"),
"latitude" : 12.36547,
"longitude" : 1.235689,
"place_name" : "some_place",
"city" : "City3"
}
{
"_id" : ObjectId("544a2147785b707b340ed6c7"),
"latitude" : 12.36547,
"longitude" : 1.235689,
"place_name" : "some_place",
"city" : "City1"
}
{
"_id" : ObjectId("544a2147785b707b340ed6c7"),
"latitude" : 12.36547,
"longitude" : 1.235689,
"place_name" : "some_place",
"city" : "City2"
}
{
"_id" : ObjectId("544a2147785b707b340ed6c7"),
"latitude" : 12.36547,
"longitude" : 1.235689,
"place_name" : "some_place",
"city" : "City2"
}
如何将具有相同城市的数据分组？意思是我需要一个包含所有具有City1的数据的数组，第二个数组包含所有具有City2的数据，依此类推。
英文:
I have a collection named "myplace" It has the following fileds place_name, city, latitude, longitude.
Doc format
{
"_id" : ObjectId("544a2147785b707b340ed6c7"),
"latitude" : 12.36547,
"longitude" : 1.235689,
"place_name" : "some_place",
"city" : "City1"
}
{
"_id" : ObjectId("544a2147785b707b340ed6c7"),
"latitude" : 12.36547,
"longitude" : 1.235689,
"place_name" : "some_place",
"city" : "City3"
}
{
"_id" : ObjectId("544a2147785b707b340ed6c7"),
"latitude" : 12.36547,
"longitude" : 1.235689,
"place_name" : "some_place",
"city" : "City1"
}
{
"_id" : ObjectId("544a2147785b707b340ed6c7"),
"latitude" : 12.36547,
"longitude" : 1.235689,
"place_name" : "some_place",
"city" : "City2"
}
{
"_id" : ObjectId("544a2147785b707b340ed6c7"),
"latitude" : 12.36547,
"longitude" : 1.235689,
"place_name" : "some_place",
"city" : "City2"
}
How can I group the data with same city? Meaning I need array of json result first array should contain all the data which having city1 second array conatins all the data which having city2 and so on
答案1
得分: 2
你可以在Mongo中更容易地完成这个操作，使用聚合框架。
db.yourCollection.aggregate([
{
$group: {
_id: "$city",
details: {
$push: {
latitude: "$latitude",
longitude: "$longitude",
place_name: "$place_name"
}
}
}
}
])
我认为这应该可以工作，但我目前无法在工作中实际尝试。希望对你有帮助！
英文:
You could do it in Mongo itself more easily in my opinion. Use the aggregation framework.
db.yourCollection.aggregate([{$group:{_id: "$city", details:{$push: {latitude: "$latitude", longitude: "$longitude", place_name:"$place_name"}}}}])
I think this should work, I can't actually try it at the moment at work. hope it helps!
答案2
得分: 1
如果你正在使用mgo，简单的排序就可以解决问题。在这里，我们首先按城市排序，然后按名称排序：
query1 := collection.Find(nil).Sort("city", "place_name")
英文:
If you are using mgo, a simple sort should do the trick. Here we search first by city and then by name:
query1 := collection.Find(nil).Sort("city", "place_name")
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论