Dumping MySQL tables to JSON with Golang

Question

Was putting together a quick dumper for MySQL to JSON in Go. However I find that everything that I retrieve from the database is a []byte array. Thus instead of n

Answer 1

I have a table named users inside practice_db database. I have mentioned the table structure with data in the following program that converts the users table into JSON format.

You can also check the source code at https://gist.github.com/hygull/1725442b0f121a5fc17b28e04796714d.

/**
    {
        "created_on": "26 may 2017",
        "todos": [
            "go get github.com/go-sql-driver/mysql",
            "postman(optional)",
            "browser(optional)",    
        ],
        "aim": "Reading fname column into []string(slice of strings)"
    }
*/


/* 
    mysql> select * from users;
    +----+-----------+----------+----------+-------------------------------+--------------+-------------------------------------------------------------------------------------------------+
    | id | fname     | lname    | uname    | email                         | contact      | profile_pic                                                                                     |
    +----+-----------+----------+----------+-------------------------------+--------------+-------------------------------------------------------------------------------------------------+
    |  1 | Rishikesh | Agrawani | hygull   | rishikesh0014051992@gmail.com | 917353787704 | https://cdn4.iconfinder.com/data/icons/rcons-user/32/user_group_users_accounts_contacts-512.png |
    |  2 | Sandeep   | E        | sandeep  | sandeepeswar8@gmail.com       | 919739040038 | https://cdn4.iconfinder.com/data/icons/eldorado-user/40/user-512.png                            |
    |  3 | Darshan   | Sidar    | darshan  | sidardarshan@gmail.com        | 917996917565 | https://cdn4.iconfinder.com/data/icons/rcons-user/32/child_boy-512.png                          |
    |  4 | Surendra  | Prajapat | surendra | surendrakgadwal@gmail.com     | 918385894407 | https://cdn4.iconfinder.com/data/icons/rcons-user/32/account_male-512.png                       |
    |  5 | Mukesh    | Jakhar   | mukesh   | mjakhar.kjakhar@gmail.com     | 919772254140 | https://cdn2.iconfinder.com/data/icons/rcons-user/32/male-circle-512.png                        |
    +----+-----------+----------+----------+-------------------------------+--------------+-------------------------------------------------------------------------------------------------+
    5 rows in set (0.00 sec)

    mysql> 
*/

package main

import "log"
import "net/http"
import "encoding/json"

import (
    _"github.com/go-sql-driver/mysql"   
    "database/sql"
)

func users(w http.ResponseWriter, r *http.Request) {
    // db, err := sql.Open("mysql", ":@tcp(127.0.0.1:)/?charset=utf8" )
    db, err := sql.Open("mysql", "hygull:admin@67@tcp(127.0.0.1:3306)/practice_db?charset=utf8")

    w.Header().Set("Content-Type", "application/json")

    if err != nil {
        log.Fatal(err)
    }

    rows, err := db.Query("select id, fname, lname, uname, email, contact, profile_pic from users")

    if err != nil {
        log.Fatal(err)
    }

    type User struct {
        Id int       `json:"id"`
        Fname string `json:"firstname"`
        Lname string `json:"lastname"`
        Uname string `json:"username"`
        Email string `json:"email"`
        Contact int `json:"contact"`
        ProfilePic string `json:"profile_pic"`
    }

    var users []User

    for rows.Next() {
        var id, contact int
        var fname string
        var lname string
        var uname, email, profile_pic string

        rows.Scan(&id ,&fname, &lname, &uname, &email, &contact, &profile_pic)
        users = append(users, User{id, fname, lname, uname, email, contact, &profile_pic })
    }

    usersBytes, _ := json.Marshal(&users)

    w.Write(usersBytes)
    db.Close()
}

func main() {
    http.HandleFunc("/users/", users)
    http.ListenAndServe(":8080", nil)
}

/* REQUSET

   http://127.0.0.1:8080/users/
*/

/* RESPONSE
[
  {
    "id": 1,
    "firstname": "Rishikesh",
    "lastname": "Agrawani",
    "username": "hygull",
    "email": "rishikesh0014051992@gmail.com",
    "contact": 917353787704,
    "profile_pic": "https://cdn4.iconfinder.com/data/icons/rcons-user/32/user_group_users_accounts_contacts-512.png"
  },
  {
    "id": 2,
    "firstname": "Sandeep",
    "lastname": "E",
    "username": "sandeep",
    "email": "sandeepeswar8@gmail.com",
    "contact": 919739040038,
    "profile_pic": "https://cdn4.iconfinder.com/data/icons/eldorado-user/40/user-512.png"
  },
  {
    "id": 3,
    "firstname": "Darshan",
    "lastname": "Sidar",
    "username": "darshan",
    "email": "sidardarshan@gmail.com",
    "contact": 917996917565,
    "profile_pic": "https://cdn4.iconfinder.com/data/icons/rcons-user/32/child_boy-512.png"
  },
  {
    "id": 4,
    "firstname": "Surendra",
    "lastname": "Prajapat",
    "username": "surendra",
    "email": "surendrakgadwal@gmail.com",
    "contact": 918385894407,
    "profile_pic": "https://cdn4.iconfinder.com/data/icons/rcons-user/32/account_male-512.png"
  },
  {
    "id": 5,
    "firstname": "Mukesh",
    "lastname": "Jakhar",
    "username": "mukesh",
    "email": "mjakhar.kjakhar@gmail.com",
    "contact": 919772254140,
    "profile_pic": "https://cdn2.iconfinder.com/data/icons/rcons-user/32/male-circle-512.png"
  }
]
*/