33 lines
1.2 KiB
JavaScript
33 lines
1.2 KiB
JavaScript
const cds = require('@sap/cds/lib')
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if (cds.requires.db?.kind === 'sqlite') {
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cds.on ('serving:AdminService', srv => srv.prepend(() => {
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const {Genres} = srv.entities
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// Register a simplistic handler for hierarchical queries
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srv.on('READ', Genres, (req,next) => {
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const q = req.query
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// Expand query on a single row
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if (q.SELECT.recurse?.where?.[0].ref[0] === 'Distance') {
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q.SELECT.from.as = 'g'
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q.SELECT.columns = q.SELECT.columns.map (c => {
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if (c.ref?.[0] === 'DrillState') return { xpr:[`
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CASE WHEN exists (
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SELECT 1 from ${Genres} where parent_ID = g.ID
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) THEN 'collapsed' ELSE 'leaf' END`
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], as: 'DrillState' }
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else return c
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})
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q.SELECT.where[0] = 'parent_ID'
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// Initial query
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} else if (!q.SELECT.search && !is_count(q)) {
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q.SELECT.where ??= [ 'parent_ID is null' ]
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}
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// Suppress error message: Feature "recurse" queries not supported.
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delete q.SELECT.__proto__.recurse
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delete q.SELECT.recurse
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return next()
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})
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}))
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}
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const is_count = q => q.SELECT.columns.length === 1 && q.SELECT.columns[0].func === 'count' |