我想要$unwind
2 个字段,school
and home
。
数据库结构就像;
{
"id" : 1,
"school" : [
{
"path" : "school1",
"code" : "code1",
},
{
"path" : "school2",
"code" : "code2",
},
{
"path" : "school3",
"code" : "code3",
},
{
"path" : "school4",
"code" : "code4",
}
],
"home" : [
{
"path" : "home1",
"code" : "homeCode1",
},
{
"path" : "home2",
"code" : "homeCode2",
},
]
}
我想要$unwind
school
and home
字段并将它们中的每一个设为;
{
"id" : 1,
"school" : [
{
"path" : "school1",
"code" : "code1",
}
},
{
"id" : 1,
"school" : [
{
"path" : "school2",
"code" : "code2",
}
},
{
"id" : 1,
"school" : [
{
"path" : "school3",
"code" : "code3",
}
},
{
"id" : 1,
"school" : [
{
"path" : "school4",
"code" : "code4",
}
},
{
"id" : 1,
"home" : [
{
"path" : "home1",
"code" : "homeCode1",
}
},
{
"id" : 1,
"home" : [
{
"path" : "home2",
"code" : "homeCode2",
}
}
我编写的旨在获取上述格式的查询是;
db.collection.aggregate([
{$unwind: "$school"},
{$unwind: "$home"}
]).pretty()
But the query
结果成对;
{
"id" : 1,
"school" : {
"path" : "school1",
"code" : "code1"
},
"home" : {
"path" : "home1",
"code" : "homeCode1"
}
}
{
"id" : 1,
"school" : {
"path" : "school1",
"code" : "code1"
},
"home" : {
"path" : "home2",
"code" : "homeCode2"
}
}
{
"id" : 1,
"school" : {
"path" : "school2",
"code" : "code2"
},
"home" : {
"path" : "home1",
"code" : "homeCode1"
}
}
{
"id" : 1,
"school" : {
"path" : "school2",
"code" : "code2"
},
"home" : {
"path" : "home2",
"code" : "homeCode2"
}
}
{
"id" : 1,
"school" : {
"path" : "school3",
"code" : "code3"
},
"home" : {
"path" : "home1",
"code" : "homeCode1"
}
}
{
"id" : 1,
"school" : {
"path" : "school3",
"code" : "code3"
},
"home" : {
"path" : "home2",
"code" : "homeCode2"
}
}
{
"id" : 1,
"school" : {
"path" : "school4",
"code" : "code4"
},
"home" : {
"path" : "home1",
"code" : "homeCode1"
}
}
{
"id" : 1,
"school" : {
"path" : "school4",
"code" : "code4"
},
"home" : {
"path" : "home2",
"code" : "homeCode2"
}
}
我怎么能够$unwind
两个字段分开,而不是这个结果对格式?