21 lines
703 B
JavaScript
21 lines
703 B
JavaScript
const cds = require('@sap/cds')
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module.exports = async function (){
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const db = await cds.connect.to('db') // connect to database service
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const { Books } = db.entities // get reflected definitions
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// Reduce stock of ordered books if available stock suffices
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this.on ('submitOrder', async req => {
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const {book,amount} = req.data
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const n = await UPDATE (Books, book)
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.with ({ stock: {'-=': amount }})
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.where ({ stock: {'>=': amount }})
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n > 0 || req.error (409,`${amount} exceeds stock for book #${book}`)
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})
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// Add some discount for overstocked books
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this.after ('READ','Books', each => {
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if (each.stock > 111) each.title += ` -- 11% discount!`
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})
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}
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