اتصال به دیتابیس PostgreSQL در برنامه‌های Golang

go get -u gorm.io/gorm
go get -u gorm.io/driver/postgres
go get github.com/joho/godotenv

DB_USER=root
DB_PASSWORD=password
DB_NAME=database_name
DB_HOST=host
DB_PORT=port
DB_SSLMODE=disable

package main

import (
    "fmt"
    "log"
    "os"

    "github.com/joho/godotenv"
    "gorm.io/driver/postgres"
    "gorm.io/gorm"
)

func main() {
    err := godotenv.Load()
    if err != nil {
        log.Fatalf("Error loading .env file")
    }

    user := os.Getenv("DB_USER")
    password := os.Getenv("DB_PASSWORD")
    dbName := os.Getenv("DB_NAME")
    host := os.Getenv("DB_HOST")
    port := os.Getenv("DB_PORT")
    sslmode := os.Getenv("DB_SSLMODE")

    dsn := fmt.Sprintf("user=%s password=%s dbname=%s host=%s port=%s sslmode=%s",
        user, password, dbName, host, port, sslmode)

    db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
    if err != nil {
        log.Fatal(err.Error())
    }

    sqlDB, err := db.DB()
    if err != nil {
        log.Fatal(err.Error())
    }
    sqlDB.SetMaxIdleConns(10)
    sqlDB.SetMaxOpenConns(100)

    log.Println("Connected to the database")
}