取表：
column column_name heading 'Name' for A10;
column DataTypeheading 'Type' FOR A16;
column NullAble heading 'NullAble' FOR A2;
column data_default heading 'default' FOR A10;
select column_name,data_type||'('||data_length||')' DataType,nullable data_default from user_tab_columns where table_name='TAB_NAME'
order by column_id;
例子结果如下：
Name Type
default
---------- ---------------- ----------
NUM_COLNUMBER(22) Y
CHAR_COL VARCHAR2(20) Y
