2

This is Database config file.config.go

type Database struct {
    conn *sql.DB
}

// global db instance
var (
    dbInstance *Database
    dbOnce     sync.Once
)

// creates a new database instance if not exist
// otherwise return the existing instance
func GetDBInstance() *Database {
    dbOnce.Do(func() {
        // Capture connection properties.
        cfg := mysql.Config{
            User:   "root",
            Passwd: "***********",
            Net:    "tcp",
            Addr:   "127.0.0.1:3306",
            DBName: "go_microservices",
        }

        // creates a pool of connection
        // not the actual database connection
        conn, err := sql.Open("mysql", cfg.FormatDSN())
        if err != nil {
            log.Error().Msg(fmt.Sprintf("database connection error %s", err))
            SendInterruptSignal()
            return
        }

        // ping the database
        // to check if the database connection is alive
        pingErr := conn.Ping()
        if pingErr != nil {
            log.Error().Msg(fmt.Sprintf("ping error %s", pingErr))
            SendInterruptSignal()
            return
        }

        // creates a new instance of DB
        dbInstance = &Database{conn: conn}
        log.Info().Msg("Successfully Connected To The Database")

    })
    return dbInstance
}

I'm trying to use that dbInstance in my handler but i'm not able to access the conn property of the instance

func (p *Product) AllProducts() []*Product {
    db := database_config.GetDBInstance()
    fmt.Printf("db: %#v\n", db)

    // db1 := database_config.GetDBInstance()
    // if db == db1 {
    //  fmt.Printf("db: %#v\n", db)
    //  fmt.Printf("db1: %#v\n", db1)

    // } else {
    //  fmt.Print("not same")
    // }

    return nil
}

when i print the object in the console. I can see the conn property in the database instance

db: &database_config.Database{conn:(*sql.DB)(0xc0002b81a0)}

When i directly return the connection. I can acess every property of db connnection but when i create a new database object with the connection. I'm not able to access anything

Tezz Bhandari
  • 31
  • 4

1 Answers1

0
  • First you have to write down struct field as first word capital, as you are importing it.

There is one more way you can write down the function that will return the connection handler.

// Get is used to get the database instance client
func Get() *sql.DB {
    return db
}
Hims1911
  • 33
  • 5