使用 Go 获取 MongoDB 中的所有模型树子节点
Get all model tree child node in MongoDB with Go
我在 MongoDB 中收集了数据。
我的数据是在模型树中构建的，child node 和 parent node 之间的关系是 属性 parentid.
这是我的数据架构
这是我的示例数据
{"_id":{"$oid":"5ebd05b52f3700008500220b"},"username":"DHBK","password":"123456","lastname":"DHBK","useremail":"dhbk@edu.com.vn","usertel":"0907111001","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":null,"comid":"DHBK","comdepartment":"DHBK","usercode":"DHBK_0001","usertype":"ADMIN_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500220c"},"username":"KHOA_DIEN","password":"123456","lastname":"KHOA_DIEN","useremail":"KHOA_DIEN@edu.com.vn","usertel":"0907111002","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"DHBK","comid":"DHBK","comdepartment":"KHOA_DIEN","usercode":"DHBK_0002","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500220d"},"username":"KHOA_XD","password":"123456","lastname":"KHOA_XD","useremail":"KHOA_XD@edu.com.vn","usertel":"0907111003","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"DHBK","comid":"DHBK","comdepartment":"KHOA_XD","usercode":"DHBK_0003","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500220e"},"username":"KHOA_CNTT","password":"123456","lastname":"KHOA_CNTT","useremail":"KHOA_CNTT@edu.com.vn","usertel":"0907111004","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"DHBK","comid":"DHBK","comdepartment":"KHOA_CNTT","usercode":"DHBK_0004","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500220f"},"username":"BOMON_TUDONG","password":"123456","lastname":"BOMON_TUDONG","useremail":"BOMON_TUDONG@edu.com.vn","usertel":"0907111005","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_DIEN","comid":"DHBK","comdepartment":"KHOA_DIEN","usercode":"DHBK_0005","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002210"},"username":"BOMON_VIENTHONG","password":"123456","lastname":"BOMON_VIENTHONG","useremail":"BOMON_VIENTHONG@edu.com.vn","usertel":"0907111006","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_DIEN","comid":"DHBK","comdepartment":"KHOA_DIEN","usercode":"DHBK_0006","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002211"},"username":"BOMON_HETHONG","password":"123456","lastname":"BOMON_HETHONG","useremail":"BOMON_HETHONG@edu.com.vn","usertel":"0907111007","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_DIEN","comid":"DHBK","comdepartment":"KHOA_DIEN","usercode":"DHBK_0007","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002212"},"username":"BOMON1_XD","password":"123456","lastname":"BOMON1_XD","useremail":"BOMON1_XD@edu.com.vn","usertel":"0907111008","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_XD","comid":"DHBK","comdepartment":"KHOA_XD","usercode":"DHBK_0008","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002213"},"username":"BOMON2_XD","password":"123456","lastname":"BOMON2_XD","useremail":"BOMON2_XD@edu.com.vn","usertel":"0907111009","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_XD","comid":"DHBK","comdepartment":"KHOA_XD","usercode":"DHBK_0009","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002214"},"username":"BOMON3_XD","password":"123456","lastname":"BOMON3_XD","useremail":"BOMON3_XD@edu.com.vn","usertel":"0907111010","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_XD","comid":"DHBK","comdepartment":"KHOA_XD","usercode":"DHBK_0010","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002215"},"username":"TRUONGKHOA_BMVT","password":"123456","lastname":"TRUONGKHOA_BMVT","useremail":"TRUONGKHOA_BMVT@edu.com.vn","usertel":"0907111011","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"BOMON_VIENTHONG","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0011","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002216"},"username":"PHOKHOA_BMVT","password":"123456","lastname":"PHOKHOA_BMVT","useremail":"PHOKHOA_BMVT@edu.com.vn","usertel":"0907111012","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"BOMON_VIENTHONG","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0012","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002217"},"username":"THUKY_BMVT","password":"123456","lastname":"THUKY_BMVT","useremail":"THUKY_BMVT@edu.com.vn","usertel":"0907111013","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"BOMON_VIENTHONG","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0013","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002218"},"username":"GV_BMVT","password":"123456","lastname":"GV_BMVT","useremail":"GV_BMVT@edu.com.vn","usertel":"0907111014","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"BOMON_VIENTHONG","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0014","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002219"},"username":"SV1_BMVT","password":"123456","lastname":"SV1_BMVT","useremail":"SV1_BMVT@edu.com.vn","usertel":"0907111015","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"GV_BMVT","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0015","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500221a"},"username":"SV2_BMVT","password":"123456","lastname":"SV2_BMVT","useremail":"SV2_BMVT@edu.com.vn","usertel":"0907111016","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"GV_BMVT","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0016","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500221b"},"username":"SV3_BMVT","password":"123456","lastname":"SV3_BMVT","useremail":"SV3_BMVT@edu.com.vn","usertel":"0907111017","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"GV_BMVT","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0017","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500221c"},"username":"SV4_BMVT","password":"123456","lastname":"SV4_BMVT","useremail":"SV4_BMVT@edu.com.vn","usertel":"0907111018","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"GV_BMVT","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0018","usertype":"USER_COM"}
{"_id":{"$oid":"5ec642b2412b0000e70021a5"},"username":"KHOA_KT","password":"123456","lastname":"KHOA_KT","useremail":"KHOA_KT@edu.com.vn","usertel":"0907111002","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"DHKT","comid":"DHBK","comdepartment":"KHOA_KT","usercode":"DHKT_0002","usertype":"USER_COM"}
{"_id":{"$oid":"5ec642b2412b0000e70021a8"},"username":"BOMON_KTDOANHNGHIEP","password":"123456","lastname":"BOMON_KTDOANHNGHIEP","useremail":"BOMON_KTDOANHNGHIEP@edu.com.vn","usertel":"0907111005","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_KT","comid":"DHBK","comdepartment":"KHOA_KT","usercode":"DHKT_0005","usertype":"USER_COM"}
{"_id":{"$oid":"5ece3517b8d5570916d013f6"},"username":"SV5_BMVT","password":"123","lastname":"SV5_BMVT","useremail":"SV5_BMVT@edu.com.vn","usertel":"0907111019","userdate":"2020-05-14","userstatus":"ACTIVE","userparentid":"GV_BMVT","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0019","usertype":"USER_COM"}
{"_id":{"$oid":"5eddf0a9b8d5570916dae6ff"},"username":"SV6_BMVT","password":"123456","lastname":"SV6_BMVT","useremail":"SV6_BMVT@edu.com.vn","usertel":"0907111020","userdate":"2020-06-08","userstatus":"ACTIVE","userparentid":"GV_BMVT","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0019","usertype":"USER_COM"}
现在我想获取特定父节点的所有子节点。例如，我想获取 DHBK node.
的所有子节点
我已完成MongoDBshell查询此需求。
这是我的MongoDBshell
var descendants=[]
var stack=[];
var item = db.users.findOne({username:"DHBK"});
stack.push(item);
while (stack.length>0){
var currentnode = stack.pop();
var children = db.users.find({userparentid:currentnode.username});
while(true === children.hasNext()) {
var child = children.next();
descendants.push(child.username);
stack.push(child);
}
}
descendants.join(",")
它有效并向我显示了正确的结果。这是我的输出结果
KHOA_DIEN,KHOA_XD,KHOA_CNTT,BOMON1_XD,BOMON2_XD,BOMON3_XD,BOMON_TUDONG,BOMON_VIENTHONG,BOMON_HETHONG,TRUONGKHOA_BMVT,PHOKHOA_BMVT,THUKY_BMVT,GV_BMVT,SV1_BMVT,SV2_BMVT,SV3_BMVT,SV4_BMVT,SV5_BMVT,SV6_BMVT
然后我写Go代码来实现这个MongoDB shell.
这是我的代码
package main
import (
"context"
"fmt"
"strings"
"time"
"go.mongodb.org/mongo-driver/bson"
"go.mongodb.org/mongo-driver/mongo"
"go.mongodb.org/mongo-driver/mongo/options"
)
func main() {
GetAllChildOfNode("DHBK")
}
func GetAllChildOfNode(node string) error {
ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
client, err := mongo.Connect(ctx, options.Client().ApplyURI("URI string"))
if err != nil {
return err
}
defer client.Disconnect(ctx)
database := client.Database("users")
users := database.Collection("users")
var descendants []string
var stack []string
err = users.FindOne(ctx, bson.M{"username": "DHBK"}).Decode(&stack)
leng := len(stack)
for leng > 0 {
//I HaVE TROUBLE HERE
currentnode := stack.
}
return nil
}
但是我在使用 Go 实现 push、pop 方法和 while loop 作为 MongoDB shell 时遇到了麻烦。
提前谢谢你。
看看您是否接受 $graphLookup 限制。
如果是这样，您可以在单个聚合查询中执行 dbside:
db.collection_name.aggregate([
{$match: {username: "DHBK"}}, // select root document
{
$graphLookup: { // load the tree as embedded docs
from: "collection_name",
startWith: "$username",
connectFromField: "username",
connectToField: "userparentid",
as: "descendants",
}
},
{$project: { // add root element if needed
descendants: {$concatArrays: [["$$ROOT"], "$descendants"] }
}},
{$unwind: "$descendants"}, // final formatting steps
{$replaceRoot: {newRoot: "$descendants"}},
{$project: {descendants:0}}
])
我在 MongoDB 中收集了数据。
我的数据是在模型树中构建的，child node 和 parent node 之间的关系是 属性 parentid.
这是我的数据架构
这是我的示例数据
{"_id":{"$oid":"5ebd05b52f3700008500220b"},"username":"DHBK","password":"123456","lastname":"DHBK","useremail":"dhbk@edu.com.vn","usertel":"0907111001","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":null,"comid":"DHBK","comdepartment":"DHBK","usercode":"DHBK_0001","usertype":"ADMIN_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500220c"},"username":"KHOA_DIEN","password":"123456","lastname":"KHOA_DIEN","useremail":"KHOA_DIEN@edu.com.vn","usertel":"0907111002","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"DHBK","comid":"DHBK","comdepartment":"KHOA_DIEN","usercode":"DHBK_0002","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500220d"},"username":"KHOA_XD","password":"123456","lastname":"KHOA_XD","useremail":"KHOA_XD@edu.com.vn","usertel":"0907111003","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"DHBK","comid":"DHBK","comdepartment":"KHOA_XD","usercode":"DHBK_0003","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500220e"},"username":"KHOA_CNTT","password":"123456","lastname":"KHOA_CNTT","useremail":"KHOA_CNTT@edu.com.vn","usertel":"0907111004","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"DHBK","comid":"DHBK","comdepartment":"KHOA_CNTT","usercode":"DHBK_0004","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500220f"},"username":"BOMON_TUDONG","password":"123456","lastname":"BOMON_TUDONG","useremail":"BOMON_TUDONG@edu.com.vn","usertel":"0907111005","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_DIEN","comid":"DHBK","comdepartment":"KHOA_DIEN","usercode":"DHBK_0005","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002210"},"username":"BOMON_VIENTHONG","password":"123456","lastname":"BOMON_VIENTHONG","useremail":"BOMON_VIENTHONG@edu.com.vn","usertel":"0907111006","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_DIEN","comid":"DHBK","comdepartment":"KHOA_DIEN","usercode":"DHBK_0006","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002211"},"username":"BOMON_HETHONG","password":"123456","lastname":"BOMON_HETHONG","useremail":"BOMON_HETHONG@edu.com.vn","usertel":"0907111007","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_DIEN","comid":"DHBK","comdepartment":"KHOA_DIEN","usercode":"DHBK_0007","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002212"},"username":"BOMON1_XD","password":"123456","lastname":"BOMON1_XD","useremail":"BOMON1_XD@edu.com.vn","usertel":"0907111008","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_XD","comid":"DHBK","comdepartment":"KHOA_XD","usercode":"DHBK_0008","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002213"},"username":"BOMON2_XD","password":"123456","lastname":"BOMON2_XD","useremail":"BOMON2_XD@edu.com.vn","usertel":"0907111009","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_XD","comid":"DHBK","comdepartment":"KHOA_XD","usercode":"DHBK_0009","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002214"},"username":"BOMON3_XD","password":"123456","lastname":"BOMON3_XD","useremail":"BOMON3_XD@edu.com.vn","usertel":"0907111010","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_XD","comid":"DHBK","comdepartment":"KHOA_XD","usercode":"DHBK_0010","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002215"},"username":"TRUONGKHOA_BMVT","password":"123456","lastname":"TRUONGKHOA_BMVT","useremail":"TRUONGKHOA_BMVT@edu.com.vn","usertel":"0907111011","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"BOMON_VIENTHONG","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0011","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002216"},"username":"PHOKHOA_BMVT","password":"123456","lastname":"PHOKHOA_BMVT","useremail":"PHOKHOA_BMVT@edu.com.vn","usertel":"0907111012","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"BOMON_VIENTHONG","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0012","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002217"},"username":"THUKY_BMVT","password":"123456","lastname":"THUKY_BMVT","useremail":"THUKY_BMVT@edu.com.vn","usertel":"0907111013","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"BOMON_VIENTHONG","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0013","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002218"},"username":"GV_BMVT","password":"123456","lastname":"GV_BMVT","useremail":"GV_BMVT@edu.com.vn","usertel":"0907111014","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"BOMON_VIENTHONG","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0014","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f37000085002219"},"username":"SV1_BMVT","password":"123456","lastname":"SV1_BMVT","useremail":"SV1_BMVT@edu.com.vn","usertel":"0907111015","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"GV_BMVT","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0015","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500221a"},"username":"SV2_BMVT","password":"123456","lastname":"SV2_BMVT","useremail":"SV2_BMVT@edu.com.vn","usertel":"0907111016","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"GV_BMVT","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0016","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500221b"},"username":"SV3_BMVT","password":"123456","lastname":"SV3_BMVT","useremail":"SV3_BMVT@edu.com.vn","usertel":"0907111017","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"GV_BMVT","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0017","usertype":"USER_COM"}
{"_id":{"$oid":"5ebd05b52f3700008500221c"},"username":"SV4_BMVT","password":"123456","lastname":"SV4_BMVT","useremail":"SV4_BMVT@edu.com.vn","usertel":"0907111018","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"GV_BMVT","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0018","usertype":"USER_COM"}
{"_id":{"$oid":"5ec642b2412b0000e70021a5"},"username":"KHOA_KT","password":"123456","lastname":"KHOA_KT","useremail":"KHOA_KT@edu.com.vn","usertel":"0907111002","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"DHKT","comid":"DHBK","comdepartment":"KHOA_KT","usercode":"DHKT_0002","usertype":"USER_COM"}
{"_id":{"$oid":"5ec642b2412b0000e70021a8"},"username":"BOMON_KTDOANHNGHIEP","password":"123456","lastname":"BOMON_KTDOANHNGHIEP","useremail":"BOMON_KTDOANHNGHIEP@edu.com.vn","usertel":"0907111005","userdate":"2020-05-05","userstatus":"ACTIVE","userparentid":"KHOA_KT","comid":"DHBK","comdepartment":"KHOA_KT","usercode":"DHKT_0005","usertype":"USER_COM"}
{"_id":{"$oid":"5ece3517b8d5570916d013f6"},"username":"SV5_BMVT","password":"123","lastname":"SV5_BMVT","useremail":"SV5_BMVT@edu.com.vn","usertel":"0907111019","userdate":"2020-05-14","userstatus":"ACTIVE","userparentid":"GV_BMVT","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0019","usertype":"USER_COM"}
{"_id":{"$oid":"5eddf0a9b8d5570916dae6ff"},"username":"SV6_BMVT","password":"123456","lastname":"SV6_BMVT","useremail":"SV6_BMVT@edu.com.vn","usertel":"0907111020","userdate":"2020-06-08","userstatus":"ACTIVE","userparentid":"GV_BMVT","comid":"DHBK","comdepartment":"BOMON_VIENTHONG","usercode":"DHBK_0019","usertype":"USER_COM"}
现在我想获取特定父节点的所有子节点。例如，我想获取 DHBK node.
我已完成MongoDBshell查询此需求。
这是我的MongoDBshell
var descendants=[]
var stack=[];
var item = db.users.findOne({username:"DHBK"});
stack.push(item);
while (stack.length>0){
var currentnode = stack.pop();
var children = db.users.find({userparentid:currentnode.username});
while(true === children.hasNext()) {
var child = children.next();
descendants.push(child.username);
stack.push(child);
}
}
descendants.join(",")
它有效并向我显示了正确的结果。这是我的输出结果
KHOA_DIEN,KHOA_XD,KHOA_CNTT,BOMON1_XD,BOMON2_XD,BOMON3_XD,BOMON_TUDONG,BOMON_VIENTHONG,BOMON_HETHONG,TRUONGKHOA_BMVT,PHOKHOA_BMVT,THUKY_BMVT,GV_BMVT,SV1_BMVT,SV2_BMVT,SV3_BMVT,SV4_BMVT,SV5_BMVT,SV6_BMVT
然后我写Go代码来实现这个MongoDB shell.
这是我的代码
package main
import (
"context"
"fmt"
"strings"
"time"
"go.mongodb.org/mongo-driver/bson"
"go.mongodb.org/mongo-driver/mongo"
"go.mongodb.org/mongo-driver/mongo/options"
)
func main() {
GetAllChildOfNode("DHBK")
}
func GetAllChildOfNode(node string) error {
ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
client, err := mongo.Connect(ctx, options.Client().ApplyURI("URI string"))
if err != nil {
return err
}
defer client.Disconnect(ctx)
database := client.Database("users")
users := database.Collection("users")
var descendants []string
var stack []string
err = users.FindOne(ctx, bson.M{"username": "DHBK"}).Decode(&stack)
leng := len(stack)
for leng > 0 {
//I HaVE TROUBLE HERE
currentnode := stack.
}
return nil
}
但是我在使用 Go 实现 push、pop 方法和 while loop 作为 MongoDB shell 时遇到了麻烦。
提前谢谢你。
看看您是否接受 $graphLookup 限制。
如果是这样，您可以在单个聚合查询中执行 dbside:
db.collection_name.aggregate([
{$match: {username: "DHBK"}}, // select root document
{
$graphLookup: { // load the tree as embedded docs
from: "collection_name",
startWith: "$username",
connectFromField: "username",
connectToField: "userparentid",
as: "descendants",
}
},
{$project: { // add root element if needed
descendants: {$concatArrays: [["$$ROOT"], "$descendants"] }
}},
{$unwind: "$descendants"}, // final formatting steps
{$replaceRoot: {newRoot: "$descendants"}},
{$project: {descendants:0}}
])