restaurant.menus
restaurant.getMenus();
There is an important dimension missing from our 'home grown' ORM implementation - relationships. As we see from the class diagram below, our Restaurants have Menus and our Menus have Menu Items.
We want to be able to access our Menus like this:
restaurant.menus
restaurant.getMenus();
and from each Menu we want to be able to access information about each item on the Menu, for example:
restaurant.menus[0].title
restaurant.getMenus().get(0).getTitle()
We therefore need to expand our Restaurant class to include a function that will add a Menu instance to the Restaurant:
addMenu(menu) {
this.menus.push(menu);
}
public void addMenu(Menu menu) {
this.menus.add(menu);
}
We can then extend our save() method to save Restaurant Menus.
save() {
const self = this;
try {
return new Promise(function (resolve) {
Restaurant.db.run(`INSERT INTO RESTAURANTS (name, image) VALUES (?, ?)`, [self.name, self.image], function (err) {
if (err) {
console.log(err.message);
throw err;
}
self.id = this.lastID; // set the object id to the inserted row id
if (self.menus) {
self.menus.forEach(async (menu) => {
// save each menu
await menu.save(self.id);
})
}
resolve(self);
})
});
} catch (err) {
console.log(err)
}
}
public Restaurant save() {
// using withHandle will auto close the db connection
Long id = jdbi.withHandle(handle -> {
return handle.createUpdate("INSERT INTO RESTAURANTS (name, imagelink) VALUES (?, ?)")
.bind(this.name, this.imageLink)
.executeAndReturnGeneratedKeys("id")
.mapTo(Long.class).findOnly();
});
for(Menu menu:menus) {
menu.save(id);
}
this.id = id;
return this;
}