小编Jon*_*Jon的帖子

给出一个表格,用于以下命令:

select sex, count(*) from my_table group by sex;
select sex, employed, count(*) from my_table group by sex, employed;

得到:

  sex  | count 
-------+------
male   | 1960 
female | 1801

和:

 sex     | employed | count 
---------+----------+-------
 male    | f        |  1523 
 male    | t        |   437 
 female  | f        |  1491 
 female  | t        |   310 

我在编写查询时遇到困难,该查询将计算每个性别组中的就业百分比.所以输出应该如下所示:

 sex     | employed | count  | percent
---------+----------+--------+-----------
 male    | f        |  1523  | 77.7% (1523/1960)
 male    | t        |   437  | …