fix: Ungrouped filtered count should contain CASE WHEN statement bu… (#7853)

* fix: Ungrouped filtered count should contain `CASE WHEN` statement but renders as `1`

* Return always ones for count and fix tests

Author: paveltiunov

packages/cubejs-schema-compiler/src/adapter/BaseQuery.js

@@ -2005,7 +2005,7 @@ export class BaseQuery {
     }
     if (this.ungrouped) {
       if (symbol.type === 'count' || symbol.type === 'countDistinct' || symbol.type === 'countDistinctApprox') {
-        return '1';
+        return evaluateSql === '*' ? '1' : this.caseWhenStatement([{ sql: `(${evaluateSql}) IS NOT NULL`, label: `1` }]);
       } else {
         return evaluateSql;
       }

packages/cubejs-schema-compiler/test/integration/postgres/pre-aggregations.test.ts

@@ -2025,6 +2025,6 @@ describe('PreAggregations', () => {
 
     expect(partitionInvalidateKeyQueries).toStrictEqual([]);
     expect(loadSql[0]).not.toMatch(/GROUP BY/);
-    expect(loadSql[0]).toMatch(/1 `real_time_lambda_visitors__count`/);
+    expect(loadSql[0]).toMatch(/THEN 1 END `real_time_lambda_visitors__count`/);
   }));
 });

packages/cubejs-schema-compiler/test/integration/postgres/sql-generation.test.ts

@@ -1435,6 +1435,30 @@ describe('SQL Generation', () => {
     }],
   }, [{ reference_visitors__google_sourced_count: '1' }]));
 
+  it('ungrouped filtered count', () => runQueryTest({
+    measures: [
+      'visitor_checkins.google_sourced_checkins',
+    ],
+    timezone: 'America/Los_Angeles',
+    order: [{
+      id: 'visitor_checkins.created_at',
+    }],
+    timeDimensions: [{
+      dimension: 'visitor_checkins.created_at',
+      granularity: 'day',
+      dateRange: ['2016-12-01', '2017-03-30'],
+    }],
+    ungrouped: true,
+    allowUngroupedWithoutPrimaryKey: true,
+  }, [
+    { visitor_checkins__created_at_day: '2017-01-02T00:00:00.000Z', visitor_checkins__google_sourced_checkins: null },
+    { visitor_checkins__created_at_day: '2017-01-03T00:00:00.000Z', visitor_checkins__google_sourced_checkins: null },
+    { visitor_checkins__created_at_day: '2017-01-04T00:00:00.000Z', visitor_checkins__google_sourced_checkins: null },
+    { visitor_checkins__created_at_day: '2017-01-04T00:00:00.000Z', visitor_checkins__google_sourced_checkins: null },
+    { visitor_checkins__created_at_day: '2017-01-04T00:00:00.000Z', visitor_checkins__google_sourced_checkins: null },
+    { visitor_checkins__created_at_day: '2017-01-05T00:00:00.000Z', visitor_checkins__google_sourced_checkins: 1 },
+  ]));
+
   it('builds geo dimension', () => runQueryTest({
     dimensions: [
       'visitors.location'