golang: example of query and update with MySQL DB

package main

 

import {

  "database/sql"

  "log"

  _ "github.com/go-sql-driver/mysql"

}

 

func dbConn() *sql.DB {

  db, err := sql.Open("mysql", 

             "myusername:mypassword@tcp(127.0.0.1:3306)/MYDB")

 

  if err != nil {

    log.Fatal(err)

  }

 

  return db

}

 

func DoQuery() (ids []int) {

  ids = nil

 

  db := dbConn()

 

  defer db.Close()

 

  res, err := db.Query("select id from mytable where name=?", "Puppy")

 

  if err != nil {

    log.Fatal(err)

  }

 

  for res.Next() {

    var id int

 

    res.Scan(&id)

 

    ids = append(ids, id)

  }

  return

}

func DoUpdate(id int) {

  db := dbConn()

 

  defer db.Close()

 

  res, err := db.Exec("update mytable set name=? where id=?", "Kitty", id)

 

  if err != nil {

    log.Fatal(err)

  }

 

  count, err := res.RowsAffected()

 

  if err != nil {

    log.Fatal(err)

  }

  log.Println(count)

}

func main() {

  ids := DoQuery()

 

  for _, id := range ids {

    DoUpdate(id)

  }

}