Oracle查看数据库结构

1.select 
    A.column_name 字段名,A.data_type 数据类型,A.data_length 长度,A.data_precision 整数位, 
    A.Data_Scale 小数位,A.nullable 允许空值,A.Data_default 缺省值,B.comments 备注 
from 
    user_tab_columns A,user_col_comments B 
where 
    A.Table_Name = B.Table_Name 
    and A.Column_Name = B.Column_Name 
    and A.Table_Name = 'AR_MSTCIMNET'; 

select * from user_tab_columns where table_name='AR_MSTCIMNET';