Beego/Golang - Query Values to Struct

Question

I have an API built in Golang using the Beego framework and I have a single query that has multiple joins and then returns a JSON result.

I was hoping there is a way for me to cast each row into a struct which has nicer key names, IE rather than "Stage__Description" just "Stage", etc... So I built a ResultMap struct with the key names I want, should I be creating a Map instead?

Query:

type ResultMap struct {
    Id        int
    DateAdded time.Time
    FirstName string
    LastName  string
    Username  string
    Stage     string
    station   string
    status    string
}

//var maps []ResultMap
var maps []orm.Params
num, err := o.QueryTable("test_result_detail").
    Filter("Result__Serial", "121994-0001").
    Values(&maps, "id", "date_added", "stage__description", "station__station", "status__status", "operator__username", "operator__first_name", "operator__last_name" )

JSON RESULT

[
  {
    "DateAdded": "2016-10-20T00:00:00-05:00",
    "Id": 8306105,
    "Operator__FirstName": "Jose",
    "Operator__LastName": "Mendez",
    "Operator__Username": "3362",
    "Stage__Description": "VR1 Test",
    "Station__Station": "TS0653",
    "Status__Status": "PASS"
  },
  {
    "DateAdded": "2016-10-20T00:00:00-05:00",
    "Id": 8306465,
    "Operator__FirstName": "Jose",
    "Operator__LastName": "Mendez",
    "Operator__Username": "3362",
    "Stage__Description": "QA Lab X-Ray Inspection",
    "Station__Station": "LABEQP-0004",
    "Status__Status": "PASS"
  },
  {
    "DateAdded": "2016-10-28T00:00:00-05:00",
    "Id": 8547267,
    "Operator__FirstName": "Jose",
    "Operator__LastName": "Mendez",
    "Operator__Username": "3362",
    "Stage__Description": "Capture Customer SN",
    "Station__Station": "N/A",
    "Status__Status": "PASS"
  },
  {
    "DateAdded": "2016-10-28T00:00:00-05:00",
    "Id": 8547851,
    "Operator__FirstName": "Jose",
    "Operator__LastName": "Mendez",
    "Operator__Username": "3362",
    "Stage__Description": "Final Test",
    "Station__Station": "TS0653",
    "Status__Status": "PASS"
  },
  {
    "DateAdded": "2017-02-14T00:00:00-06:00",
    "Id": 10993864,
    "Operator__FirstName": "Jose",
    "Operator__LastName": "Mendez",
    "Operator__Username": "3362",
    "Stage__Description": "QA Mechanical Final Inspection",
    "Station__Station": "VISUAL INSPECTION",
    "Status__Status": "PASS"
  }
]

MahlerFive · Accepted Answer · 2017-02-23T20:38:59.640

You want to use json annotations on your struct, then use json.Unmarshal to put the data into your struct.

Here is an example:

package main

import (
    "encoding/json"
    "fmt"
)

func main() {
    // The struct you want to store the data in
    // Note the json tags that show which json field corresponds to which struct field
    type Data struct {
        FirstName string `json:"Operator__FirstName"`
        LastName  string `json:"Operator__LastName"`
    }
    // Create a slice of these structs since our json is an array of results
    var structData []Data

    // The json you want to dump into the structs
    jsonData := []byte(`[{"Operator__FirstName": "Bob", "Operator__LastName": "Smith"},{"Operator__FirstName": "John", "Operator__LastName": "Adams"}]`)

    _ = json.Unmarshal(jsonData, &structData)

    fmt.Printf("%+v", structData)
}

And here it is in Go Playground: https://play.golang.org/p/Z2P7oUVT9i

Can you show how I would iterate over my maps object above with multiple results? — xXPhenom22Xx, Feb 23 '17 at 15:12
I updated the example above to handle a json array with multiple results. Basically you just need to create a slice of your structs and unmarshal into that instead. — MahlerFive, Feb 23 '17 at 20:39

Drizzt · Answer 2 · 2021-07-16T10:00:04.633

You can also use MVC pattern. If you want to use MVC, you need to create models package and register the model to database.

package models

import (
"time"

"github.com/astaxie/beego/orm"
)

type ResultMap struct {
    Id        int    `orm:"auto"`
    DateAdded time.Time    `orm:"type(datetime)"`
    FirstName string     `orm:"size(255)"`
    LastName  string     `orm:"size(255)"`
    Username  string     `orm:"size(255)"`
    Stage     string     `orm:"size(255)"`
    station   string     `orm:"size(255)"`
    status    string     `orm:"size(255)"`
}

func init() {
    orm.RegisterModel(
        new(ResultMap),
    )
}

Then you can select your data as model in your controller as you want(slice or single variable).

func main() {
    var mySlice []models.ResultMap
    _,err := orm.NewOrm().QueryTable("ResultMap").Filter("FirstName","Bob").All(&mySlice)
    if err != nil {
        fmt.Println("Database Error: ",err)
        return
    }

    for _, value := range mySlice {
        fmt.Println("Firstname: ",value.FirstName)
    }
}

You can check model definition and ORM usage

Beego/Golang - Query Values to Struct

2 Answers2