oralce小数点问题

Question

问个问题，我有个字段a,存储的是金额，怎么让小数点后面保留4位小数啊，不足4位的补0

Answer 1

select to_char(123.13,'FM9999999999999999999.0000') a from dual

Answer 2

select to_char(123,'FM9999999999999999999.0000') a from dual------------------
  A
1 123.0000

Answer 3

SQL> create table test_hyx(n number(16,4));Table createdSQL> insert into test_hyx values (44.23);1 row insertedSQL> commit;Commit completeSQL> select * from test_hyx;                 N
------------------
           44.2300SQL> drop table test_hyx;Table droppedSQL>