Files
cloud-cap-samples/graphql/srv/bookshop-service.js
2022-02-24 08:30:26 +01:00

12 lines
443 B
JavaScript

module.exports = function() {
const { Orders, Books } = this.entities
this.before('CREATE', Orders, async function(req) {
const { book_ID, quantity } = req.data
// reduce the stock, if enough are available, else reject the order
const applied = await UPDATE(Books, book_ID).set({ stock: { '-=': quantity } }).where({ stock: { '>=': quantity }})
if (!applied) req.reject(400, `Sorry, ${quantity} are not in stock`)
})
}