golang 結構體內嵌結構體序列化填充

看我上一篇隨筆 https://www.cnblogs.com/zengxm/p/13473340.html

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其中使用mysql原始語句查詢結果並返回

 

上一篇隨筆代碼

 

 

並想直接映射到結構體中,后來發現結構體序列化時有個坑

這次實際操作了一下解決了

代碼如下

type Curriculums struct {
    CID         int            `gorm:"column:c_id" json:"cid"`
    UID         int            `gorm:"column:u_id" json:"uid"`
    //TID         int            `gorm:"column:t_id" json:"tid"`
    Name         string        `gorm:"column:c_name" json:"title"`
    Price         float64        `gorm:"column:price" json:"price"`
    Info        string        `gorm:"column:info" json:"info"`
    Image        string        `gorm:"column:c_image" json:"img"`
    CreateTime     *time.Time    `gorm:"column:create_at" json:"at"`
    DeleteTime     *time.Time    `gorm:"column:delete_at" json:"et"`

    AdminDelTime      *time.Time        `gorm:"column:admin_del" json:"a_del"`        // 后台人員刪除時間
    Aid               int                `gorm:"column:a_id" json:"aid"`                // 后台執行人信息
}
func (cr *Curriculums)TableName()string{
    return "curriculums"
}
type User struct {
    ID             uint64        `gorm:"column:u_id" json:"uid,omitempty"`
    Nickename     string        `gorm:"column:nickename" json:"nick,omitempty"`
    Username     string        `gorm:"column:username" json:"uname,omitempty"`
    Pswd         string        `gorm:"column:pswd" json:"pswd,omitempty"`
    Status         int            `gorm:"column:status" json:"st,omitempty"`
    RID         int            `gorm:"column:r_id" json:"rid,omitempty"`
    Portrait     string        `gorm:"column:portrait" json:"img,omitempty"`
    CreateTime     *time.Time    `gorm:"column:create_at" json:"at,omitempty"`

    AdminDelTime      *time.Time        `gorm:"column:admin_del" json:"a_del,omitempty"`        // 后台人員刪除時間
    Aid               int                `gorm:"column:a_id" json:"aid,omitempty"`                // 后台執行人信息
}
func (u *User)TableName()string{
    return "users"
}

type SelectData struct {
    User
    JsonStr string   `gorm:"column:datas" json:"datas,omitempty"`
    MarshalerData []Curriculums        `json:"datas,omitempty" `
}




func main(){
    var result []SelectData

    SQL := "SELECT u.u_id,u.nickename,u.username, " +
        "CONCAT(\"[\",GROUP_CONCAT('{','\"cid\":',c.c_id,',\"title\":\"',c.c_name,'\",\"price\":',c.price,',\"info\":\"',c.info,'\"}'),\"]\") as datas " +
        "FROM users AS u " +
        "JOIN curriculums AS c " +
        "ON c.u_id = u.u_id " +
        "WHERE c.c_name like '%o%' GROUP BY u.u_id"

    conn.Raw(SQL).Scan(&result)

    for index,_ := range result{

        result[index].JsonStr = strings.Replace(result[index].JsonStr,"\n","",-1)

        //fmt.Println(result[index])
        /*
        {{100000 acfun 7745742641  0 0  <nil> <nil> 0} [{"cid":102,"title":"python 學習","price":20.00,"info":"python "},{"cid":103,"title":"golang 學習","price":70.79,"info":"go語言 gin框架"}] {[]}}
        {{100006 giligililllsa666 z99999es  0 0  <nil> <nil> 0} [{"cid":117,"title":"測試保存視頻,視頻url保存在阿里雲oss上","price":9.99,"info":"test in"}] {[]}}
        */
        b,err := json.Marshal(result[index])
        if err != nil {
            panic(err)
        }

        fmt.Println(string(b))
        /*
 上面輸出與序列化對比丟失了 datas 數據 {"uid":100000,"nick":"acfun","uname":"7745742641"} {"uid":100006,"nick":"giligililllsa666","uname":"z99999es"} 
       */
    }
}

后來經過排查發現是結構體中內嵌結構體並被命名后產生的坑

type SelectData struct {
    User
    JsonStr string   `gorm:"column:datas" json:"datas,omitempty"`
    MarshalerData []Curriculums        `json:"datas,omitempty" `   # 內嵌結構體被命名了,被命名內嵌結構體如果不指定該命名則不會序列化
    
}

 

避免產生則需要添加一個中間結構體,修改如下

type Mid struct {
    d []Curriculums        // 小寫避免被序列化
}

type SelectData struct {
    User
    JsonStr string   `gorm:"column:datas" json:"datas,omitempty"`   
    //MarshalerData []Curriculums        `json:"datas,omitempty" `
    Mid
}

success:
 {"uid":100000,"nick":"acfun","uname":"7745742641","datas":"[{\"cid\":102,\"title\":\"python 學習\",\"price\":20.00,\"info\":\"python \"},{\"cid\":103,\"title\":\"golang 學習\",\"price\":70.79,\"info\":\"go語言 gin框架\"}]"}
      {"uid":100006,"nick":"giligililllsa666","uname":"z99999es","datas":"[{\"cid\":117,\"title\":\"測試保存視頻,視頻url保存在阿里雲oss上\n\",\"price\":9.99,\"info\":\"test in\"}]"}

 

 

下次記得使用原始sql語句查詢結果並序列化是對內嵌結構體需要注意~~~~~~~~~~~~~~~~

 

參考資料:

https://www.cnblogs.com/staff/p/13223443.html

https://www.it1352.com/809480.html (重點)

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本筆記自用 而已，如有錯誤請指正！