UPDATE Geo_postaggregated_pop_count_Ward
SET Sum_male_count =
        (SELECT SUM(G.Person_count)
      FROM Geo_postaggregated_pop_count_Ward G
      WHERE Sex = 1);

UPDATE Geo_postaggregated_pop_count_Ward
      SET Sum_female_count =
              (SELECT SUM(G.Person_count)
            FROM Geo_postaggregated_pop_count_Ward G
            WHERE Sex = 2);

UPDATE Geo_postaggregated_pop_count_Ward
            SET Sum_of_person_count =
                    (SELECT SUM(G.Person_count)
                  FROM Geo_postaggregated_pop_count_Ward G
                  WHERE Sex = 1 OR
                       Sex = 2);