Oracle中SQL查询表字段基本信息、主键、外键(转)

select utc.column_name,
       utc.data_type,
       utc.data_length,
       utc.data_precision,
       utc.data_Scale,
       utc.nullable,
       utc.data_default,
       ucc.comments,
       utc.table_name
  from user_tab_columns utc, user_col_comments ucc
 where utc.table_name = ucc.table_name
   and utc.column_name = ucc.column_name
   and utc.table_name in (select upper(tb.table_name)
                            from all_tables tb
                           where tb.OWNER = 'USER_NAME')
 order by column_id

注意：order by column_id的意义是使得结果按照设计数据结构时的顺序显示。

二，查询表主键

select
col.column_name
from
user_constraints con,user_cons_columns col
where
con.constraint_name=col.constraint_name and con.constraint_type='P'
and col.table_name='ONLINEXLS'
三，查询表外键

select
distinct(ucc.column_name) column_name,rela.table_name,rela.column_name column_name1
from
user_constraints uc,user_cons_columns ucc,
(select t2.table_name,t2.column_name,t1.r_constraint_name from user_constraints t1,user_cons_columns t2 where t1.r_constraint_name=t2.constraint_name and t1.table_name='ONLINEXLS') rela
where
uc.constraint_name=ucc.constraint_name
and uc.r_constraint_name=rela.r_constraint_name
and uc.table_name='ONLINEXLS'

有了上述几个SQL语句，再结合程序（如：java+jxl），就可以输出如下图所示的Excel报表了。

本篇文章来源于 Linux公社网站(www.linuxidc.com)  原文链接：http://www.linuxidc.com/Linux/2011-08/41830.htm