fix(hana): Ensure xpr with logical operator to only contain comparisons

hana/lib/HANAService.js

@@ -647,7 +647,9 @@ class HANAService extends SQLService {
     }
 
     where(xpr) {
-      return this.xpr({ xpr: [...xpr, 'THEN'] }).slice(0, -4)
+      xpr = { xpr }
+      const suffix = this.is_comparator(xpr) ? '' : ' = TRUE'
+      return `${this.xpr(xpr)}${suffix}`
     }
 
     having(xpr) {
@@ -673,6 +675,7 @@ class HANAService extends SQLService {
         */
       }
 
+      let endWithCompare = false
       if (!_internal) {
         for (let i = 0; i < xpr.length; i++) {
           let x = xpr[i]
@@ -683,6 +686,7 @@ class HANAService extends SQLService {
             // HANA does not support comparators in all clauses (e.g. SELECT 1>0 FROM DUMMY)
             // HANA does not have an 'IS' or 'IS NOT' operator
             if (x in compareOperators) {
+              endWithCompare = true
               const left = xpr[i - 1]
               const right = xpr[i + 1]
               const ifNull = compareOperators[x]
@@ -725,16 +729,25 @@ class HANAService extends SQLService {
       for (let i = 0; i < xpr.length; ++i) {
         const x = xpr[i]
         if (typeof x === 'string') {
+          const up = x.toUpperCase()
+          if (up in logicOperators) {
+            // Force current expression to end with a comparison
+            endWithCompare = true
+          }
+          if (endWithCompare && (up in caseOperators || up === ')')) {
+            endWithCompare = false
+          }
           sql.push(this.operator(x, i, xpr))
         } else if (x.xpr) sql.push(`(${this.xpr(x, caseSuffix)})`)
         // default
         else sql.push(this.expr(x))
       }
 
-      // HANA does not allow WHERE TRUE so when the expression is only a single entry "= TRUE" is appended
-      if (caseSuffix && (
-        xpr.length === 1 || xpr.at(-1) === '')) {
-        sql.push(caseSuffix)
+      if (endWithCompare) {
+        const suffix = this.operator('OR', xpr.length, xpr).slice(0, -3)
+        if (suffix) {
+          sql.push(suffix)
+        }
       }
 
       return `${sql.join(' ')}`
@@ -765,13 +778,14 @@ class HANAService extends SQLService {
      * @returns
      */
     is_comparator({ xpr }, start) {
+      const local = start != null
       for (let i = start ?? xpr.length; i > -1; i--) {
         const cur = xpr[i]
         if (cur == null) continue
         if (typeof cur === 'string') {
           const up = cur.toUpperCase()
           // When a compare operator is found the expression is a comparison
-          if (up in compareOperators) return true
+          if (up in compareOperators || (!local && up in logicOperators)) return true
           // When a case operator is found it is the start of the expression
           if (up in caseOperators) break
           continue

test/scenarios/bookshop/read.test.js

@@ -171,6 +171,14 @@ describe('Bookshop - Read', () => {
     expect(res4[1].title).to.be.eq('dracula')
   })
 
+  test('Filter Books(multiple functions)', async () => {
+    const res = await GET(
+      `/admin/Books?$filter=contains(descr,'Edgar') or contains(descr,'Autobiography')`,
+      admin,
+    )
+    expect(res.data.value.length).to.be.eq(3)
+  })
+
   test.skip('Insert Booky', async () => {
     const res = await POST(
       '/admin/Booky',