fix: use "$$value$$" as internal column name for UPSERT

db-service/lib/cqn2sql.js

@@ -741,10 +741,10 @@ class CQN2SQLRenderer {
 
     const extractkeys = managed
       .filter(c => keys.includes(c.name))
-      .map(c => `${c.onInsert || c.sql} as ${this.quote(c.name)}`)
+      .map(c => `${(c.onInsert || c.sql).replace('"$$value$$"', 'value')} as ${this.quote(c.name)}`)
 
     const entity = this.name(q.target?.name || UPSERT.into.ref[0], q)
-    sql = `SELECT ${managed.map(c => c.upsert)} FROM (SELECT value, ${extractkeys} from json_each(?)) as NEW LEFT JOIN ${this.quote(entity)} AS OLD ON ${keyCompare}`
+    sql = `SELECT ${managed.map(c => c.upsert)} FROM (SELECT value as "$$value$$", ${extractkeys} from json_each(?)) as NEW LEFT JOIN ${this.quote(entity)} AS OLD ON ${keyCompare}`
 
     const updateColumns = columns.filter(c => {
       if (keys.includes(c)) return false //> keys go into ON CONFLICT clause
@@ -1126,9 +1126,10 @@ class CQN2SQLRenderer {
 
   managed_extract(name, element, converter) {
     const { UPSERT, INSERT } = this.cqn
+    const value = UPSERT ? '"$$value$$"' : 'value'
     const extract = !(INSERT?.entries || UPSERT?.entries) && (INSERT?.rows || UPSERT?.rows)
-      ? `value->>'$[${this.columns.indexOf(name)}]'`
-      : `value->>'$."${name.replace(/"/g, '""')}"'`
+      ? `${value}->>'$[${this.columns.indexOf(name)}]'`
+      : `${value}->>'$."${name.replace(/"/g, '""')}"'`
     const sql = converter?.(extract) || extract
     return { extract, sql }
   }
@@ -1139,7 +1140,8 @@ class CQN2SQLRenderer {
   }
 
   managed_default(name, managed, src) {
-    return `(CASE WHEN json_type(value,${this.managed_extract(name).extract.slice(8)}) IS NULL THEN ${managed} ELSE ${src} END)`
+    const value = this.cqn.INSERT ? 'value' : '"$$value$$"'
+    return `(CASE WHEN json_type(${value},${this.managed_extract(name).extract.slice(value.length + 3)}) IS NULL THEN ${managed} ELSE ${src} END)`
   }
 }
 

test/bookshop/db/schema.cds

@@ -68,4 +68,9 @@ entity C : managed {
       toB : Composition of many B
               on toB.ID = $self.B;
 };
+
+entity Values {
+  key ID : Integer;
+  value  : String;
+}
 entity BooksAnnotated as projection on Books;

test/scenarios/bookshop/upsert.test.js

@@ -0,0 +1,16 @@
+const cds = require('../../cds.js')
+const bookshop = cds.utils.path.resolve(__dirname, '../../bookshop')
+
+describe('Bookshop - Upsert', () => {
+  const { expect } = cds.test(bookshop)
+
+  test.only('upsert data with "value" as column name', async () => {
+    // in our UPSERT logic we used "value" as internal column
+    // which led to an ambiguous column error if the entity has an element with the same name
+    const { Values } = cds.entities
+    const upsert = UPSERT({ ID: 201, value: 42 }).into(Values)
+    const res = await upsert;
+    expect(res).to.eql(1)
+  })
+
+})