where is go packages located code example

Example: commonly used go packages

package main
 
import (
    "github.com/jinzhu/gorm"
    _ "github.com/jinzhu/gorm/dialects/sqlite"
)
 
type Product struct {
  gorm.Model
  Code string
  Price uint
}
 
func main() {
  db, err := gorm.Open("sqlite3", "test.db")
  if err != nil {
    panic("failed to connect database")
  }
  defer db.Close()
 
  // Migrate the schema
  db.AutoMigrate(&Product{})
 
  // Create
  db.Create(&Product{Code: "L1212", Price: 1000})
 
  // Read
  var product Product
  db.First(&product, 1) // find product with id 1
  db.First(&product, "code = ?", "L1212")
 
  // Update - update product's price to 2000
  db.Model(&product).Update("Price", 2000)
 
  // Delete - delete product
  db.Delete(&product)