求个SQL语句哈!

Question

想对一个表作个修改:原表:               1               2                 3          4 
-----------------------------------------------------------------
             a                 b                 1          3
             a                 b                 1          2
             b                 c                 1          1
             b                 d                 1          0
能不能转化成:
              1               统计(就是列"3"都是1的统计个数)     3                   
  -----------------------------------------------------------------
              a               2                              1
              b               2                              1
谢谢!

Answer 1

select  1,count(3),'1' from table where 3='1' group by 1 

Answer 2

select  1,count(1), 3 from table where 3= '1 ' group by 1