✨ backend: Adding support for select based on null values and negation (#525)

tdrive/backend/node/src/core/platform/services/database/services/orm/connectors/postgres/postgres-query-builder.ts

@@ -47,9 +47,18 @@ export class PostgresQueryBuilder {
               values.push(...inClause);
             }
           } else {
-            const value = `${this.dataTransformer.toDbString(filter, columnsDefinition[key].type)}`;
-            whereClause += `${key} = $${idx++} AND `;
-            values.push(value);
+            const isANotEqualFilter = filter && Object.keys(filter).join("") === "$ne";
+            if (filter === null || (isANotEqualFilter && filter["$ne"] === null)) {
+              whereClause += `${key} IS${filter === null ? "" : " NOT"} NULL`;
+            } else {
+              const filterValue = isANotEqualFilter ? filter["$ne"] : filter;
+              const value = `${this.dataTransformer.toDbString(
+                filterValue,
+                columnsDefinition[key].type,
+              )}`;
+              whereClause += `${key} ${isANotEqualFilter ? "!=" : "="} $${idx++} AND `;
+              values.push(value);
+            }
           }
         });
     }

tdrive/backend/node/test/unit/core/services/database/services/orm/connectors/postgres/postgres-query-builder.test.ts

@@ -105,6 +105,42 @@ describe('The PostgresQueryBuilder', () => {
     expect(query[1]).toEqual(options.$like.map(e=> `%${e[1]}%`));
   });
 
+  test('buildSelect query with IS NULL filter', async () => {
+    //given
+    const filters = { companu_id: null };
+
+    //when
+    const query = subj.buildSelect(TestDbEntity, filters, {});
+
+    //then
+    expect(normalizeWhitespace(query[0] as string)).toBe(`SELECT * FROM \"test_table\" WHERE companu_id IS NULL ORDER BY id DESC LIMIT 100 OFFSET 0`);
+    expect(query[1]).toEqual([]);
+  });
+
+  test('buildSelect query with not equal filter', async () => {
+    //given
+    const filters = { company_id: { $ne: '123' } };
+
+    //when
+    const query = subj.buildSelect(TestDbEntity, filters, {});
+
+    //then
+    expect(normalizeWhitespace(query[0] as string)).toBe(`SELECT * FROM "test_table" WHERE company_id != $1 ORDER BY id DESC LIMIT 100 OFFSET 0`);
+    expect(query[1]).toEqual([ '123' ]);
+  });
+
+  test('buildSelect query with IS NOT NULL filter', async () => {
+    //given
+    const filters = { company_id: { $ne: null } };
+
+    //when
+    const query = subj.buildSelect(TestDbEntity, filters, {});
+
+    //then
+    expect(normalizeWhitespace(query[0] as string)).toBe(`SELECT * FROM "test_table" WHERE company_id IS NOT NULL ORDER BY id DESC LIMIT 100 OFFSET 0`);
+    expect(query[1]).toEqual([]);
+  });
+
   test('buildDelete query', async () => {
     //given
     const entity = newTestDbEntity();