3 Replies Latest reply: Jan 17, 2013 2:28 AM by Frank Kulash RSS

    Count Functions

    Rahul_India
      craete table t (a number);
      
      insert into t values(null);
      insert into t values(null);
      insert into t values(1);
      insert into t values(2);
      insert into t values(3);
      insert into t values(2);
      
      commit;
      
      
      select count(*) from t;
      6-- count every row
      
      select count(all a) from t;
      4-- does not count null
      
      select count(distinct a) from t;
      3---does not count
      so do all group functions ignore null?