1. Install the github.com/go-sql-driver/mysql and github.com/gorilla/mux packages, using the go get command, as follows:

$ go get github.com/go-sql-driver/mysql
$ go get github.com/gorilla/mux

2. Create update-record-mysql.go. Then we connect to the MySQL database, update the name of an employee for an ID, and write the number of records updated in a database to an HTTP response stream, as follows:

package main
import 
(
  "database/sql"
  "fmt"
  "log"
  "net/http" 
  "github.com/go-sql-driver/mysql"
  "github.com/gorilla/mux"
)
const 
(
  CONN_HOST = "localhost"
  CONN_PORT = "8080"
  DRIVER_NAME = "mysql"
  DATA_SOURCE_NAME = "root:password@/mydb"
)
var db *sql.DB
var connectionError error 
func init() 
{
  db, connectionError = sql.Open(DRIVER_NAME, DATA_SOURCE_NAME)
  if connectionError != nil 
  {
    log.Fatal("error connecting to database :: ", connectionError)
  }
}
type Employee struct 
{
  Id   int    `json:"uid"`
  Name string `json:"name"`
}
func updateRecord(w http.ResponseWriter, r *http.Request) 
{
  vars := mux.Vars(r)
  id := vars["id"]
  vals := r.URL.Query()
  name, ok := vals["name"]
  if ok 
  {
    log.Print("going to update record in database 
    for id :: ", id)
    stmt, err := db.Prepare("UPDATE employee SET name=? 
    where uid=?")
    if err != nil 
    {
      log.Print("error occurred while preparing query :: ", err)
      return
    }
    result, err := stmt.Exec(name[0], id)
    if err != nil 
    {
      log.Print("error occurred while executing query :: ", err)
      return
    }
    rowsAffected, err := result.RowsAffected()
    fmt.Fprintf(w, "Number of rows updated in database 
    are :: %d",rowsAffected)
  } 
  else 
  {
    fmt.Fprintf(w, "Error occurred while updating record in 
    database for id :: %s", id)
  }
}
func main() 
{
  router := mux.NewRouter()
  router.HandleFunc("/employee/update/{id}",
  updateRecord).Methods("PUT")
  defer db.Close()
  err := http.ListenAndServe(CONN_HOST+":"+CONN_PORT, router)
  if err != nil 
  {
    log.Fatal("error starting http server :: ", err)
    return
  }
}

3. Run the program with the following command: 

$ go run update-record-mysql.go