migration

package main

import (
    "database/sql"
    "encoding/json"
    "fmt"
    "os"

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

//connect to database
func dbConn() (db *sql.DB) {
    dbDriver := "mysql"
    dbUser := "root"
    dbPass := "root"
    dbName := "upwork"
    db, err := sql.Open(dbDriver, dbUser+":"+dbPass+"@/"+dbName)
    if err != nil {
        panic(err.Error())
    }
    return db
}

type topicItem struct {
    Id        int    `json:"id"`
    FileExist bool   `json:"file_exist`
    ItemPiLoc string `json:"item_pi_loc"`
}

type Result struct {
    Status   bool        `json:"status"`
    Response interface{} `json:"response"`
    Error    string      `json:"error"`
}

func getVideoDetail(data []int) (Result, error) {
    var id int
    var itemPiLoc string
    db := dbConn()
    // we need define field list when run select query as will need for scan method
    sqlStatement := `SELECT id,item_pi_loc FROM TopicItems WHERE item_id =? and item_type_id= 1 order by item_order;`
    row := db.QueryRow(sqlStatement, data[1])

    result := Result{}

    switch err := row.Scan(&id, &itemPiLoc); err {
    case nil:
        fileName := "..%sCourseResource%s%d%svideos%s%d%s%s"
        dirPath := string(os.PathSeparator)
        fileName = fmt.Sprintf(fileName, dirPath, dirPath, data[0], dirPath, dirPath, data[1], dirPath, itemPiLoc)
        topic := topicItem{Id: id, ItemPiLoc: itemPiLoc}
        if _, err := os.Stat(fileName); err == nil {
            topic.FileExist = true
        }
        result.Status = true
        result.Response = topic
    default:
        result.Response = nil
        result.Error = err.Error()
    }
    return result, nil
}

func main() {
    data := []int{2, 1}
    result, _ := getVideoDetail(data)

    response, _ := json.Marshal(result)

    fmt.Println(string(response))

}