Group aggregation supports multiple columns for postgres (#6483)

* Group aggregation supports multiple columns for postgres

* Group aggregation supports multiple columns for postgres

* Group aggregation supports multiple columns for postgres

* Group aggregation supports multiple columns for postgres

spec/ParseQuery.Aggregate.spec.js

@@ -225,6 +225,32 @@ describe('Parse.Query Aggregate testing', () => {
       });
   });
 
+  it('group by multiple columns ', done => {
+    const obj1 = new TestObject();
+    const obj2 = new TestObject();
+    const obj3 = new TestObject();
+    const pipeline = [
+      {
+        group: {
+          objectId: {
+            score: '$score',
+            views: '$views',
+          },
+          count: { $sum: 1 },
+        },
+      },
+    ];
+    Parse.Object.saveAll([obj1, obj2, obj3])
+      .then(() => {
+        const query = new Parse.Query(TestObject);
+        return query.aggregate(pipeline);
+      })
+      .then(results => {
+        expect(results.length).toEqual(5);
+        done();
+      });
+  });
+
   it('group by date object', done => {
     const obj1 = new TestObject();
     const obj2 = new TestObject();
@@ -963,25 +989,29 @@ describe('Parse.Query Aggregate testing', () => {
     await Parse.Object.saveAll([obj1, obj2, obj3, obj4, obj5, obj6]);
 
     expect(
-      (await new Parse.Query('MyCollection').aggregate([
-        {
-          match: {
-            language: { $in: [null, 'en'] },
+      (
+        await new Parse.Query('MyCollection').aggregate([
+          {
+            match: {
+              language: { $in: [null, 'en'] },
+            },
           },
-        },
-      ]))
+        ])
+      )
         .map(value => value.otherField)
         .sort()
     ).toEqual([1, 2, 3, 4]);
 
     expect(
-      (await new Parse.Query('MyCollection').aggregate([
-        {
-          match: {
-            $or: [{ language: 'en' }, { language: null }],
+      (
+        await new Parse.Query('MyCollection').aggregate([
+          {
+            match: {
+              $or: [{ language: 'en' }, { language: null }],
+            },
           },
-        },
-      ]))
+        ])
+      )
         .map(value => value.otherField)
         .sort()
     ).toEqual([1, 2, 3, 4]);

src/Adapters/Storage/Postgres/PostgresStorageAdapter.js

@@ -2219,20 +2219,30 @@ export class PostgresStorageAdapter implements StorageAdapter {
             groupValues = value;
             const groupByFields = [];
             for (const alias in value) {
-              const operation = Object.keys(value[alias])[0];
-              const source = transformAggregateField(value[alias][operation]);
-              if (mongoAggregateToPostgres[operation]) {
+              if (typeof value[alias] === 'string' && value[alias]) {
+                const source = transformAggregateField(value[alias]);
                 if (!groupByFields.includes(`"${source}"`)) {
                   groupByFields.push(`"${source}"`);
                 }
-                columns.push(
-                  `EXTRACT(${
-                    mongoAggregateToPostgres[operation]
-                  } FROM $${index}:name AT TIME ZONE 'UTC') AS $${index +
-                    1}:name`
-                );
                 values.push(source, alias);
+                columns.push(`$${index}:name AS $${index + 1}:name`);
                 index += 2;
+              } else {
+                const operation = Object.keys(value[alias])[0];
+                const source = transformAggregateField(value[alias][operation]);
+                if (mongoAggregateToPostgres[operation]) {
+                  if (!groupByFields.includes(`"${source}"`)) {
+                    groupByFields.push(`"${source}"`);
+                  }
+                  columns.push(
+                    `EXTRACT(${
+                      mongoAggregateToPostgres[operation]
+                    } FROM $${index}:name AT TIME ZONE 'UTC') AS $${index +
+                      1}:name`
+                  );
+                  values.push(source, alias);
+                  index += 2;
+                }
               }
             }
             groupPattern = `GROUP BY $${index}:raw`;