stem/stemdb/start.go

package stemdb

import (
	"fmt"
	"os"

	_ "github.com/go-sql-driver/mysql"
	"github.com/jmoiron/sqlx"
)

// The above type represents a book with properties such as ID, author, series, title, and flags for
// deletion and selection.
// @property {int} ID - The ID property is an integer that represents the unique identifier of a book.
// @property {string} Author - The author of the book.
// @property {string} Seria - The "Seria" property in the Book struct represents the series to which
// the book belongs. It is a string that holds the name or identifier of the series.
// @property {string} Title - The title of the book.
// @property {bool} Deleted - The "Deleted" property is a boolean value that indicates whether the book
// has been marked as deleted or not. If the value is true, it means the book has been deleted. If the
// value is false, it means the book is not deleted.
// @property {bool} Selected - The "Selected" property is a boolean value that indicates whether the
// book is currently selected or not. It can be used to keep track of which books are currently being
// interacted with or displayed in a user interface.
type Book struct {
	ID       int
	Author   string
	Seria    string
	Title    string
	Deleted  bool
	Selected bool
}

var dbx *sqlx.DB

// The Connect function opens a connection to a MySQL database and returns the connection object.
func Connect() *sqlx.DB {
	db, err := sqlx.Open("mysql", "itman:X753951x@(xigmanas:3306)/stem")
	checkError("open db", err)
	dbx = db
	return db
}

// возвращает список всех книг
// возможно использование фильтров в query, типа: ?deleted=deleted&selected=not selected
// The function `ListAllBooks` retrieves a list of books from a database based on optional conditions.
func ListAllBooks(options ...string) ([]Book, error) {
	cmd := `
		SELECT
			id, author, seria, title, 
			deleted, selected
		FROM
			book
	`
	// блок условий
	where := ""
	if options != nil {
		where = "WHERE 1=1"
		for _, o := range options {
			if o != "" {
				where += fmt.Sprintf(" AND %s", o)
			}
		}
	}

	//fmt.Printf("where: %s\n", where)
	var books []Book
	err := dbx.Select(&books, cmd+where)
	//checkError("ListBooks", err)
	return books, err
}

// поскольку это отдельный пакет, то приходится дублировать
// ============================ разные утилиты ==========================

// Проверяет наличие ошибки
// The function "checkError" is used to print and exit the program if an error occurs.
func checkError(src string, err error) {
	if err != nil {
		fmt.Printf("[db] (%s): %s\n", src, err)
		os.Exit(1)
	}
}