07-06-Melvin-Gorutine/pool_manager.go
2025-10-01 06:42:15 -04:00

76 lines
1.9 KiB
Go

package main
import (
"context"
"database/sql"
"fmt"
"time"
_ "github.com/lib/pq"
)
var DB *sql.DB
func InitDB() {
dbURL := "postgres://5803024006:5803024006@202.46.28.160:45432/tgs03_5803024006?sslmode=disable"
var err error
DB, err = sql.Open("postgres", dbURL)
if err != nil {
panic(err)
}
// setting pool
DB.SetMaxOpenConns(10)
DB.SetMaxIdleConns(5)
DB.SetConnMaxLifetime(time.Minute * 5)
// test koneksi
ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
defer cancel()
if err = DB.PingContext(ctx); err != nil {
panic(fmt.Sprintf("gagal koneksi database: %v", err))
}
fmt.Println("✅ Database connected!")
}
// ===== CRUD Contoh =====
func CreateUser(name, email string) (int, error) {
var id int
err := DB.QueryRow(`INSERT INTO users (name, email) VALUES ($1, $2) RETURNING id`, name, email).Scan(&id)
return id, err
}
func CreateCourse(title, desc string) (int, error) {
var id int
err := DB.QueryRow(`INSERT INTO courses (title, description) VALUES ($1, $2) RETURNING id`, title, desc).Scan(&id)
return id, err
}
func EnrollUser(userID, courseID int) error {
_, err := DB.Exec(`INSERT INTO enrollments (user_id, course_id) VALUES ($1, $2) ON CONFLICT (user_id, course_id) DO NOTHING`, userID, courseID)
return err
}
func ListEnrollments() error {
rows, err := DB.Query(`SELECT u.name, c.title, e.created_at
FROM enrollments e
JOIN users u ON e.user_id = u.id
JOIN courses c ON e.course_id = c.id`)
if err != nil {
return err
}
defer rows.Close()
fmt.Println("=== Enrollments ===")
for rows.Next() {
var name, title string
var created time.Time
_ = rows.Scan(&name, &title, &created)
fmt.Printf("%s enrolled in %s at %v\n", name, title, created)
}
return nil
}