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PoC: Extend Map capabilities #1436

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44 changes: 42 additions & 2 deletions db-service/lib/cqn2sql.js
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Original file line number Diff line number Diff line change
Expand Up @@ -683,6 +683,9 @@
if (z.args) {
return _aliased(`${this.quote(this.name(z, q))}${this.from_args(z.args)}`)
}
if (ref.length > 1) {
return `${this.from({ ref: [from.ref[0]], as })}, json_each((${this.Map_extract({ ref: [as, ...from.ref.slice(1)], as, _from: true })}))`
}
return _aliased(this.quote(this.name(z, q)))
}
if (from.SELECT) return _aliased(`(${this.SELECT(from)})`)
Expand Down Expand Up @@ -1257,14 +1260,51 @@
* @param {import('./infer/cqn').ref} param0
* @returns {string} SQL
*/
ref({ ref }) {
ref(org) {
const { ref, element, _from } = org

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'_from' is assigned a value but never used
switch (ref[0]) {
case '$now': return this.func({ func: 'session_context', args: [{ val: '$now', param: false }] }) // REVISIT: why do we need param: false here?
case '$user': return this.func({ func: 'session_context', args: [{ val: '$user.' + ref[1] || 'id', param: false }] }) // REVISIT: same here?
default: return ref.map(r => this.quote(r)).join('.')
default: return !element?.parent || ref.length > 2
? this.Map_extract(org)
: ref.map(r => this.quote(r)).join('.')
}
}

Map_extract({ ref, _from }) {
ref = [...ref]
let src = this._from_value || (this.cqn._target instanceof cds.builtin.classes.Map && !_from)
? ['value']
: ref.splice(0, 2)

src = src.map(r => this.quote(r)).join('.')

const level = (src, path, first) => {
let p = []

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'p' is assigned a value but never used
let star = false
const sql = path.reduce((sql, cur, i, arr) => {
if (star) return sql
const id = cur.id || cur
if (id === '*') {
star = true
const where = cur.where
this._from_value = true
sql = `SELECT ${first
? `json_group_array(${level('value', arr.slice(i + 1))})`
: level('value', arr.slice(i + 1))} FROM json_each((${src})->>${this.string(sql)})${where ? ` WHERE ${this.where(where)}` : ''}`

this._from_value = undefined
return sql
}
return `${sql}.${JSON.stringify(id)}`
}, '$')

return star ? sql : sql === '$' ? src : `(${src})->>${this.string(sql)}`
}

return `(${level(src, ref, true)})`
}

/**
* Renders a value into the correct SQL syntax or a placeholder for a prepared statement
* @param {import('./infer/cqn').val} param0
Expand Down
70 changes: 39 additions & 31 deletions db-service/lib/cqn4sql.js
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Original file line number Diff line number Diff line change
Expand Up @@ -458,7 +458,10 @@ function cqn4sql(originalQuery, model) {
if (leaf.virtual === true) return

let baseName
if (col.ref.length >= 2) {
if (leaf instanceof cds.builtin.classes.Map) {
baseName = col.ref[0]
col.as ??= col.ref.at(-1)
} else if (col.ref.length >= 2) {
baseName = col.ref
.map(idOnly)
.slice(col.ref[0] === tableAlias ? 1 : 0, col.ref.length - 1)
Expand Down Expand Up @@ -1209,7 +1212,7 @@ function cqn4sql(originalQuery, model) {
columnAlias = column.as || column.ref.slice(0, -1).map(idOnly).join('_')
} else baseName = getFullName(column.$refLinks[column.$refLinks.length - 1].definition)

if(column.element && !isAssocOrStruct(column.element)) {
if (column.element && !isAssocOrStruct(column.element)) {
columnAlias = column.as || leafAssocIndex === -1 ? columnAlias : column.ref.slice(leafAssocIndex - 1).map(idOnly).join('_')
const res = { ref: [tableAlias, calculateElementName(column)], as: columnAlias }
setElementOnColumns(res, column.element)
Expand Down Expand Up @@ -1336,7 +1339,9 @@ function cqn4sql(originalQuery, model) {
})
return flatRefs
}
const flatRef = tableAlias ? { ref: [tableAlias, baseName] } : { ref: [baseName] }
const flatRef = element instanceof cds.builtin.classes.Map
? tableAlias ? { ref: [tableAlias, ...column.ref] } : { ref: [...column.ref] }
: tableAlias ? { ref: [tableAlias, baseName] } : { ref: [baseName] }
if (column.cast) {
flatRef.cast = column.cast
if (!columnAlias)
Expand All @@ -1345,7 +1350,7 @@ function cqn4sql(originalQuery, model) {
}
if (column.sort) flatRef.sort = column.sort
if (columnAlias) flatRef.as = columnAlias
setElementOnColumns(flatRef, element)
setElementOnColumns(flatRef, column.element ?? element)
defineProperty(flatRef, '_csnPath', csnPath)
return [flatRef]

Expand Down Expand Up @@ -1499,7 +1504,7 @@ function cqn4sql(originalQuery, model) {
throw new Error(`The operator "${next}" can only be used with scalar operands`)

const newTokens = expandComparison(token, ops, rhs, $baseLink)
if(newTokens.length === 0)
if (newTokens.length === 0)
throw new Error(`Can't compare two empty structures`)

const needXpr = Boolean(tokenStream[i - 1] || tokenStream[indexRhs + 1])
Expand Down Expand Up @@ -1534,9 +1539,9 @@ function cqn4sql(originalQuery, model) {
const lastAssoc =
token.isJoinRelevant && [...token.$refLinks].reverse().find(l => l.definition.isAssociation)
const tableAlias = getTableAlias(token, (!lastAssoc?.onlyForeignKeyAccess && lastAssoc) || $baseLink)
if(isAssocOrStruct(definition)) {
const flat = getFlatColumnsFor(token, { tableAlias: $baseLink?.alias || tableAlias })
if(flat.length === 0)
if (isAssocOrStruct(definition)) {
const flat = getFlatColumnsFor(token, { tableAlias: $baseLink?.alias || tableAlias })
if (flat.length === 0)
throw new Error(`Structured element “${getFullName(definition)}” expands to nothing and can't be used in expressions`)
else if (flat.length > 1 && context.prop !== 'list') // only acceptable in `list`
throw new Error(`Structured element “${getFullName(definition)}” expands to multiple fields and can't be used in expressions`)
Expand Down Expand Up @@ -1654,7 +1659,7 @@ function cqn4sql(originalQuery, model) {
const leaf = def.$refLinks[def.$refLinks.length - 1]
const first = def.$refLinks[0]
const tableAlias = getTableAlias(def, def.ref.length > 1 && first.definition.isAssociation ? first : $baseLink)
if (leaf.definition.parent.kind !== 'entity')
if (leaf.definition.parent?.kind !== 'entity')
// we need the base name
return getFlatColumnsFor(leaf.definition, {
baseName: def.ref
Expand All @@ -1669,7 +1674,7 @@ function cqn4sql(originalQuery, model) {

function assertNoStructInXpr(token, context) {
const definition = token.$refLinks?.at(-1).definition
if(!definition) return
if (!definition) return
const rejectStructs = context && (context.prop in { where: 1, having: 1 })
// unmanaged is always forbidden
// expanding a ref in a `where`/`having` context
Expand Down Expand Up @@ -1748,6 +1753,7 @@ function cqn4sql(originalQuery, model) {
let next = $refLinksReverse[i + 1]
const nextStep = refReverse[i + 1] // only because we want the filter condition

if (!current) continue // TODO: ensure that it is happening inside a Map
if (current.definition.target && next) {
const { where, ...args } = nextStep
if (isStructured(next.definition)) {
Expand Down Expand Up @@ -1781,7 +1787,7 @@ function cqn4sql(originalQuery, model) {

// OData variant w/o mentioning key
if (refReverse[0].where?.length === 1 && refReverse[0].where[0].val) {
filterConditions.push(getTransformedTokenStream(refReverse[0].where,{ $baseLink: $refLinksReverse[0] }))
filterConditions.push(getTransformedTokenStream(refReverse[0].where, { $baseLink: $refLinksReverse[0] }))
}

if (existingWhere.length > 0) filterConditions.push(existingWhere)
Expand Down Expand Up @@ -1814,7 +1820,9 @@ function cqn4sql(originalQuery, model) {
const subquerySource =
getDefinition(transformedFrom.$refLinks[0].definition.target) || transformedFrom.$refLinks[0].target
const id = getLocalizedName(subquerySource)
transformedFrom.ref = [subquerySource.params ? { id, args: from.ref.at(-1).args || {} } : id]
transformedFrom.ref = transformedFrom.$refLinks[0].definition instanceof cds.builtin.classes.Map
? [id, ...transformedFrom.ref.slice(1)]
: [subquerySource.params ? { id, args: from.ref.at(-1).args || {} } : id]

return { transformedWhere, transformedFrom }
}
Expand Down Expand Up @@ -2227,19 +2235,19 @@ function cqn4sql(originalQuery, model) {
return SELECT
}

/**
* For a given search term calculate a search expression which can be used in a where clause.
* The search function is pushed to a subquery and the primary key(s) of the entity is/are used to match
* the search results of the subquery.
*
* @param {object} searchTerm - The search expression which shall be applied to the searchable columns on the query source.
* @param {object} query - The FROM clause of the CQN statement.
*
* @returns {(Object|null)} returns either:
* - an expression of the form `<primaryKey> in (select <primaryKey> from <entity> where search(<searchableColumns>, <searchTerm>))`
* - a function with two arguments: The first one being the list of searchable columns, the second argument holds the search expression.
* - or null, if no searchable columns are found in neither in `@cds.search` nor in the target entity itself.
*/
/**
* For a given search term calculate a search expression which can be used in a where clause.
* The search function is pushed to a subquery and the primary key(s) of the entity is/are used to match
* the search results of the subquery.
*
* @param {object} searchTerm - The search expression which shall be applied to the searchable columns on the query source.
* @param {object} query - The FROM clause of the CQN statement.
*
* @returns {(Object|null)} returns either:
* - an expression of the form `<primaryKey> in (select <primaryKey> from <entity> where search(<searchableColumns>, <searchTerm>))`
* - a function with two arguments: The first one being the list of searchable columns, the second argument holds the search expression.
* - or null, if no searchable columns are found in neither in `@cds.search` nor in the target entity itself.
*/
function getSearch(searchTerm, query) {
const entity = query.SELECT.from.SELECT ? query.SELECT.from : cds.infer.target(query) // REVISIT: we should reliably use inferred._target instead
const searchIn = computeColumnsToBeSearched(inferred, entity)
Expand All @@ -2255,13 +2263,13 @@ function cqn4sql(originalQuery, model) {
// for aggregated queries / search on subqueries we do not do a subquery search
if (inferred.SELECT.groupBy || entity.SELECT)
return searchFunc

const matchColumns = getPrimaryKey(entity)
if (matchColumns.length === 0 || searchIn.every(r => r.ref.length === 1)) // keyless or not deep, fallback to old behavior
return searchFunc
const subquery = SELECT.from(entity).columns(...matchColumns).where(searchFunc)
return { xpr: [ matchColumns.length === 1 ? matchColumns[0] : {list: matchColumns}, 'in', subquery] }

const subquery = SELECT.from(entity).columns(...matchColumns).where(searchFunc)
return { xpr: [matchColumns.length === 1 ? matchColumns[0] : { list: matchColumns }, 'in', subquery] }
}

/**
Expand All @@ -2278,7 +2286,7 @@ function cqn4sql(originalQuery, model) {
if (!node || !node.$refLinks || !node.ref) {
throw new Error('Invalid node')
}
if(node.$refLinks[0].$main) {
if (node.$refLinks[0].$main) {
if (node.isJoinRelevant) {
return getJoinRelevantAlias(node)
}
Expand Down Expand Up @@ -2421,7 +2429,7 @@ function assignQueryModifiers(SELECT, modifiers) {
else SELECT.having.push('and', ...val)
} else if (key === 'where') {
// ignore OData shortcut variant: `… bookshop.Orders:items[2]`
if(!val || val.length === 1 && val[0].val) continue
if (!val || val.length === 1 && val[0].val) continue
if (!SELECT.where) SELECT.where = val
// infix filter comes first in resulting where
else SELECT.where = [...(hasLogicalOr(val) ? [asXpr(val)] : val), 'and', ...(hasLogicalOr(SELECT.where) ? [asXpr(SELECT.where)] : SELECT.where)]
Expand Down
22 changes: 18 additions & 4 deletions db-service/lib/infer/index.js
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Original file line number Diff line number Diff line change
Expand Up @@ -106,11 +106,14 @@ function infer(originalQuery, model) {
if (ref.length > 1) {
target = from.ref.slice(1).reduce((d, r) => {
const next = getDefinition(d.elements[r.id || r]?.target) || d.elements[r.id || r]
if (!next) throw new Error(`No association “${r.id || r}” in ${d.kind} “${d.name}”`)
if (!next) {
if (d instanceof cds.builtin.classes.Map) return d
throw new Error(`No association “${r.id || r}” in ${d.kind} “${d.name}”`)
}
return next
}, target)
}
if (target.kind !== 'entity' && !target.isAssociation)
if (target.kind !== 'entity' && !target.isAssociation && !(target instanceof cds.builtin.classes.Map))
throw new Error('Query source must be a an entity or an association')

inferArg(from, null, null, { inFrom: true, $mainLazyResolve })
Expand All @@ -121,7 +124,7 @@ function infer(originalQuery, model) {
? getImplicitAlias(first, useTechnicalAlias)
: getImplicitAlias(ref.at(-1).id || ref.at(-1), useTechnicalAlias))
if (alias in querySources) throw new Error(`Duplicate alias "${alias}"`)
querySources[alias] = { definition: getDefinition(target.name), args }
querySources[alias] = { definition: getDefinition(target.name) || target, args }
const last = from.$refLinks.at(-1)
last.alias = alias
} else if (from.args) {
Expand Down Expand Up @@ -515,6 +518,13 @@ function infer(originalQuery, model) {
definition: getDefinitionFromSources(sources, id),
target: getDefinitionFromSources(sources, id),
})
} else if (Object.keys($combinedElements).length === 0) {
const definition = new cds.builtin.classes.Map()
definition.type = definition._type
definition.ref = arg.ref
const $refLink = { definition, target: sources[Object.keys(sources)[0]] }
arg.$refLinks.push($refLink)
nameSegments.push(id)
} else {
stepNotFoundInCombinedElements(id) // REVISIT: fails with {__proto__:elements)
}
Expand All @@ -531,6 +541,9 @@ function infer(originalQuery, model) {
)
}

// It is not possible to know what is inside a Map column
if(definition instanceof cds.builtin.classes.Map) break

const target = getDefinition(definition.target) || arg.$refLinks[i - 1].target
if (element) {
if ($baseLink && inInfixFilter) {
Expand Down Expand Up @@ -961,6 +974,7 @@ function infer(originalQuery, model) {
for (let i = 0; i < column.ref.length; i++) {
const ref = column.ref[i]
const link = column.$refLinks[i]
if (link.definition instanceof cds.builtin.classes.Map) break
if (link.definition.on && link.definition.isAssociation) {
if (!column.ref[i + 1]) {
if (column.expand && assoc) return true
Expand Down Expand Up @@ -1088,7 +1102,7 @@ function infer(originalQuery, model) {
function getElementForCast(thing) {
const { cast, $refLinks } = thing
if (!cast) return {}
if ($refLinks?.[$refLinks.length - 1].definition.elements)
if ($refLinks?.[$refLinks.length - 1].definition.elements && !($refLinks?.[$refLinks.length - 1].definition instanceof cds.builtin.classes.Map))
// no cast on structure
cds.error`Structured elements can't be cast to a different type`
thing.cast = cdsTypes[cast.type] || cast
Expand Down
49 changes: 49 additions & 0 deletions test/compliance/SELECT.test.js
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Original file line number Diff line number Diff line change
Expand Up @@ -241,6 +241,55 @@ describe('SELECT', () => {
assert.strictEqual(res[0].static.length, 1)
})

test('path expression into Map column', async () => {
const { map } = cds.entities('basic.literals')
await INSERT([
{ map: { a: { b: [{ c: true }, { d: false }] } } },
{ map: { a: { b: [{ c: 1 }, { d: 0 }] } } },
]).into(map)

const obj = await cds.ql`SELECT map.a as extract FROM ${map}`
expect(obj).deep.eq([
{ extract: { b: [{ c: true }, { d: false }] } },
{ extract: { b: [{ c: 1 }, { d: 0 }] } },
])
const arr = await cds.ql`SELECT map.a.b as extract FROM ${map}`
expect(arr).deep.eq([
{ extract: [{ c: true }, { d: false }] },
{ extract: [{ c: 1 }, { d: 0 }] },
])

// REVISIT: can't cast "d" into :Boolean as the result type is :array<Boolean>
const star = await cds.ql`SELECT map.a.b.![*].d as extract FROM ${map}`
expect(star).deep.eq([
{ extract: [null, 0] },
{ extract: [null, 0] },
])
const infix = await cds.ql`SELECT map.a.b.![*][d != null].d as extract FROM ${map}`
expect(infix).deep.eq([
{ extract: [0] },
{ extract: [0] },
])

const table = await cds.ql`SELECT c:Boolean, d:Boolean FROM ${map}:map.a.b`
expect(table).deep.eq([
{ c: true, d: null },
{ c: null, d: false },
{ c: true, d: null },
{ c: null, d: false },
])
const where = await cds.ql`SELECT c:Boolean, d:Boolean FROM ${map}:map.a.b WHERE d != null`
expect(where).deep.eq([
{ c: null, d: false },
{ c: null, d: false },
])
const tblfix = await cds.ql`SELECT c:Boolean, d:Boolean FROM ${map}:map.a.b.![*][c != null]`
expect(tblfix).deep.eq([
{ c: true, d: null },
{ c: true, d: null },
])
})

test.skip('invalid cast (wrong)', async () => {
const { globals } = cds.entities('basic.projection')
const cqn = cds.ql`SELECT 'String' as ![string] : cds.DoEsNoTeXiSt FROM ${globals}`
Expand Down
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