// Package example demonstrates basic Go structures
package example
import (
"fmt"
"time"
)
// Config holds application configuration
type Config struct {
Host string
Port int
}
// Logger is an interface for logging operations
type Logger interface {
Log(message string) error
LogError(err error)
}
// DatabaseManager manages database connections and queries
type DatabaseManager struct {
connectionString string
connected bool
}
// NewDatabaseManager creates a new DatabaseManager instance
func NewDatabaseManager(connStr string) *DatabaseManager {
return &DatabaseManager{
connectionString: connStr,
connected: false,
}
}
// Connect establishes database connection
func (db *DatabaseManager) Connect() error {
fmt.Println("Connecting to database")
db.connected = true
return nil
}
// Disconnect closes database connection
func (db *DatabaseManager) Disconnect() {
if db.connected {
fmt.Println("Disconnecting from database")
db.connected = false
}
}
// Query executes a SQL query and returns results
func (db *DatabaseManager) Query(sql string) ([]map[string]interface{}, error) {
return nil, nil
}
// UserService handles user-related operations
type UserService struct {
db *DatabaseManager
}
// CreateUser creates a new user in the database
func (s *UserService) CreateUser(username, email string) (int, error) {
return 1, nil
}
// GetUser retrieves user by ID
func (s *UserService) GetUser(userID int) (map[string]interface{}, error) {
return nil, nil
}
// DeleteUser deletes a user by ID
func (s *UserService) DeleteUser(userID int) error {
return nil
}
// ValidateEmail validates email format
func ValidateEmail(email string) bool {
return len(email) > 0 && email[0] != '@'
}
// FormatTimestamp formats a timestamp to string
func FormatTimestamp(t time.Time) string {
return t.Format("2006-01-02 15:04:05")
}
// main is the entry point
func main() {
db := NewDatabaseManager("postgresql://localhost/mydb")
db.Connect()
fmt.Println("Application started")
}
