在Mongo集合游标中添加嵌套结构

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我在将嵌套结构附加到数组时遇到问题。

两者都有不同的嵌套值，但在附加最后一个结构时，它会覆盖第一个嵌套结构。

这是这个概念的一个简单示例。 （我尝试复制附加嵌套结构，但它工作正常）https://play.golang.org/p/psethzv33ul

这是我实际代码中的结构

type initiative struct {
    oid          primitive.objectid `bson:"_id,omitempty"json:"id,omitempty"`
    cid          string             `json:"cid"`
    name         string             `json:"name"`
    description  string             `json:"description"`
    productname  string             `json:"product_name"`
    productid    string             `json:"product_id"`
    quarter      string             `json:"quarter"`
    year         string             `json:"year"`
    customfields []nestedfield            `json:"custom_fields"`
}

type nestedfield struct {
    id    string `json:"id"`
    cid   string `json:"cid"`
    name  string `json:"name"`
    type  string `json:"type"`
    form  string `json:"form"`
    value string `json:"value"`
}

type initiativeresponse struct {
    errorcode        string       `json:"error_code,omitempty"`
    errordescription string       `json:"error_description,omitempty"`
    message          string       `json:"message,omitempty"`
    payload          []initiative `json:"payload,omitempty"`
}

这就是我的职责。

func getinitiativesfromdb(d *database.mongodb, cid string) (response initiativeresponse, err error) {
    filter := bson.m{"cid": cid}
    cur, err := d.database.collection(initiativecollection).find(context.background(), filter, options.find())
    fmt.printf("%#v", cur)
    if err != nil {
        return response, errors.errorresponse{"no initiatives were found", 404}
    }
    var initiative initiative
    for cur.next(context.background()) {
        err := cur.decode(&initiative)
        if err != nil {
            return response, errors.errorresponse{"no initiatives were found", 404}
        }
        response.payload = append(response.payload, initiative)
        fmt.printf("%#v", response.payload)
    }
    if err := cur.err(); err != nil {
        return response, errors.errorresponse{"no initiatives were found", 404}
    }
    _ = cur.close(context.background())
    return response, nil
}

这是我在第一次和第二次附加后打印数组的值时发现的。

请注意，第一次 nestedfields 的值与第二次附加后的值不同。

首先追加

[]api.initiative{
    api.initiative{
        oid:primitive.objectid{0x5d, 0xd9, 0x3f, 0x96, 0xd2, 0xc6, 0xb2, 0x95, 0x19, 0xd2, 0xbf, 0x98}, 
        cid:"5d8502a2a284b46f3621f389", 
        name:"1", 
        description:"", 
        productname:"", 
        productid:"", 
        quarter:"", 
        year:"", 
        customfields:[]api.nestedfield{
            api.nestedfield{
                id:"5db8ec9fee8040e9b6dfad87", 
                cid:"5d8502a2a284b46f3621f389", 
                name:"test", 
                type:"text", 
                form:"initiative", 
                value:"ggg"}, 
            api.nestedfield{
                id:"5dba0bcedf9cbf185683ecca", 
                cid:"5d8502a2a284b46f3621f389", 
                name:"kylie", 
                type:"text", 
                form:"initiative", 
                value:"ggg"}, 
            api.nestedfield{
                id:"5dd71d2af20bea1fef4564eb", 
                cid:"5d8502a2a284b46f3621f389", 
                name:"asdfasdf", 
                type:"text", 
                form:"initiative", 
                value:"ggg"}}}}

第二个追加

[]api.initiative{
    api.initiative{
        oid:primitive.objectid{0x5d, 0xd9, 0x3f, 0x96, 0xd2, 0xc6, 0xb2, 0x95, 0x19, 0xd2, 0xbf, 0x98}, 
        cid:"5d8502a2a284b46f3621f389", 
        name:"1", 
        description:"", 
        productname:"", 
        productid:"", 
        quarter:"", 
        year:"", 
        customfields:[]api.nestedfield{
            api.nestedfield{
                id:"5db8ec9fee8040e9b6dfad87", 
                cid:"5d8502a2a284b46f3621f389", 
                name:"test", 
                type:"text", 
                form:"initiative", 
                value:"aaa"}, 
            api.nestedfield{
                id:"5dba0bcedf9cbf185683ecca", 
                cid:"5d8502a2a284b46f3621f389", 
                name:"kylie", 
                type:"text", 
                form:"initiative", 
                value:"aaa"}, 
            api.nestedfield{
                id:"5dd71d2af20bea1fef4564eb", 
                cid:"5d8502a2a284b46f3621f389", 
                name:"asdfasdf", 
                type:"text", 
                form:"initiative", 
                value:""}}}, 
    api.initiative{
        oid:primitive.objectid{0x5d, 0xd9, 0x3f, 0x9f, 0xd2, 0xc6, 0xb2, 0x95, 0x19, 0xd2, 0xbf, 0x99}, 
        cid:"5d8502a2a284b46f3621f389", 
        name:"2", 
        description:"", 
        productname:"", 
        productid:"", 
        quarter:"", 
        year:"", 
        customfields:[]api.nestedfield{
            api.nestedfield{
                id:"5db8ec9fee8040e9b6dfad87", 
                cid:"5d8502a2a284b46f3621f389", 
                name:"test", 
                type:"text", 
                form:"initiative", 
                value:"aaa"}, 
            api.nestedfield{
                id:"5dba0bcedf9cbf185683ecca", 
                cid:"5d8502a2a284b46f3621f389", 
                name:"kylie", 
                type:"text", 
                form:"initiative", 
                value:"aaa"}, 
            api.nestedfield{
                id:"5dd71d2af20bea1fef4564eb", 
                cid:"5d8502a2a284b46f3621f389", 
                name:"asdfasdf", 
                type:"text",
                form:"initiative", 
                value:""}}}}

以及打印cur的结果

&mongo.Cursor{
    Current:bson.Raw(nil), 
    bc:(*driver.BatchCursor)(0xc000204000), 
    batch:(*bsoncore.DocumentSequence)(nil), 
    registry:(*bsoncodec.Registry)(0xc0000ee070), 
    clientSession:(*session.Client)(0xc0001f40c0), err:error(nil)}

有谁知道为什么会发生这种情况或如何解决它？

解决方案

我发现当我在循环内移动 var initiative initiative 时，它工作得很好。

func GetInitiativesFromDB(d *database.MongoDB, cid string) (response InitiativeResponse, err error) {
    filter := bson.M{"cid": cid}
    cur, err := d.Database.Collection(INITIATIVECOLLECTION).Find(context.Background(), filter, options.Find())
    fmt.Printf("%#v", cur)
    if err != nil {
        return response, errors.ErrorResponse{"No initiatives were found", 404}
    }
    for cur.Next(context.Background()) {
        var initiative Initiative
        err := cur.Decode(&initiative)
        if err != nil {
            return response, errors.ErrorResponse{"No initiatives were found", 404}
        }
        response.Payload = append(response.Payload, initiative)
        fmt.Printf("%#v", response.Payload)
    }
    if err := cur.Err(); err != nil {
        return response, errors.ErrorResponse{"No initiatives were found", 404}
    }
    _ = cur.Close(context.Background())
    return response, nil
}

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