number(p>,s>)

精度p取值范圍1～38
有效位s取值范圍-84～127

最高整數位數＝p-s

s正數，小數點右邊指定位置開始四舍五入
s負數，小數點左邊指定位置開始四舍五入
s是0或者未指定，四舍五入到最近整數
當p小于s時候，表示數字是絕對值小于1的數字，且從小數點右邊開始的前s-p 位必須是0，保留s位小數。

Connected to Oracle9i Enterprise Edition Release 9.0.1.1.1
Connected as aspire

SQL>
SQL> SET linesize 1000;
SQL> CREATE TABLE hjm_num_test
2 (a NUMBER,
3 b NUMBER(5,2),
4 c NUMBER(5,-2),
5 d NUMBER(5,0),
6 e NUMBER(5),
7 f NUMBER(2,5));

Table created

SQL> INSERT INTO hjm_num_test
2 (a,b,c,d,e,f) VALUES(123.3333,123.3333,123.3333,123.3333,123.3333,-0.0003);

1 row inserted

SQL> INSERT INTO hjm_num_test
2 (a,b,c,d,e,f) VALUES(197.9333,197.9333,197.9333,197.9333,197.9333,0.00012567);

1 row inserted

SQL> COMMIT;

Commit complete

SQL> SELECT * FROM hjm_num_test;