oracle的number型为什么只能显示16位数？我小数点本来后面有10位，现在只能显示5位了

我测试是没问题的:

WOSON at myhome> create table test_number (a number (38,20));

Table created.

WOSON at myhome> insert into test_number values (123456789012345678.90123456789012345678);

1 row created.

WOSON at myhome> select * from test_number;

A
----------
1.2346E+17

1 row selected.

WOSON at myhome> col a format 999999999999999999.99999999999999999999
WOSON at myhome> select * from test_number;

A
----------------------------------------
123456789012345678.90123456789012345678

1 row selected.

WOSON at myhome> commit;

Commit complete.

参考:

NUMBER(p,s)

where:

p is the precision, or the total number of significant decimal digits, where the most significant digit is the lef