fix: wrong falsy checks for vals in list optimization (#797)

hana/lib/HANAService.js

@@ -979,13 +979,13 @@ class HANAService extends SQLService {
  list(list) {
  const first = list.list[0]
  // If the list only contains of lists it is replaced with a json function and a placeholder
- if (this.values && first.list && !first.list.find(v => !v.val)) {
+ if (this.values && first.list && !first.list.find(v => v.val == null)) {
  const extraction = first.list.map((v, i) => `"${i}" ${this.constructor.InsertTypeMap[typeof v.val]()} PATH '$.V${i}'`)
  this.values.push(JSON.stringify(list.list.map(l => l.list.reduce((l, c, i) => { l[`V${i}`] = c.val; return l }, {}))))
  return `(SELECT * FROM JSON_TABLE(?, '$' COLUMNS(${extraction})))`
  }
  // If the list only contains of vals it is replaced with a json function and a placeholder
- if (this.values && first.val) {
+ if (this.values && first.val != null) {
  const v = first
  const extraction = `"val" ${this.constructor.InsertTypeMap[typeof v.val]()} PATH '$.val'`
  this.values.push(JSON.stringify(list.list))
@@ -1111,6 +1111,7 @@ class HANAService extends SQLService {
  // JavaScript types
  string: () => `NVARCHAR(2147483647)`,
  number: () => `DOUBLE`,
+ boolean: () => `NVARCHAR(5)`,
 
  // HANA types
  'cds.hana.TINYINT': () => 'INT',