@Test
  public void countIfDistinctTest() {
    String[] expectedHeader =
        new String[] {
          "device_id",
          "_col1",
          "_col2",
          "_col3",
          "_col4",
          "_col5",
          "_col6",
          "_col7",
          "_col8",
          "_col9",
          "_col10"
        };
    String[] retArray = new String[] {"d01,0,1,1,1,1,1,1,1,1,1,"};
    tableResultSetEqualTest(
        "select device_id, count_if(distinct s1 < 0), count_if(distinct s2 is not null), count_if(distinct s3 is not null), count_if(distinct s4 is not null), count_if(distinct s5 is not null), count_if(distinct s6 is not null), count_if(distinct s7 is not null), count_if(distinct s8 is not null), count_if(distinct s9 is not null), count_if(distinct s10 is not null) "
            + "from table1 group by 1 order by 1",
        expectedHeader,
        retArray,
        DATABASE_NAME);
  }
In this Class, we construct the scenario using DistinctAccumulator for
AggregationFunctionDistinct. Other cases are covered by {@link IoTDBTableViewAggregationIT}.
integration-test/src/test/java/org/apache/iotdb/relational/it/query/view/recent/IoTDBTableViewAggregationFunctionDistinctIT.java