oracle查询表结构语句

select o.table_name, tmp.comments, o.COLUMN_NAME, t.comments, o.DATA_TYPE
|| CASE TRIM(o.DATA_TYPE)
WHEN 'DATE' THEN
''
WHEN 'NUMBER' THEN
case when o.DATA_PRECISION is not null then
'(' || o.DATA_PRECISION || ',' || o.DATA_SCALE || ')'
else '' end
WHEN 'CHAR' THEN
'(' || o.DATA_LENGTH || ')'
WHEN 'VARCHAR2' THEN
'(' || o.DATA_LENGTH || ')'
END AS DATA_TYPE,
o.NULLABLE,
o.SEGMENT_COLUMN_ID,
const.COLUMN_NAME,
case when const.COLUMN_NAME is null then 'N' else 'Y' end as PI
from user_tab_cols o
inner join user_col_comments t on (t.table_name=o.TABLE_NAME and t.column_name=o.COLUMN_NAME)
left join (select t.table_name, c.comments
from user_tables t
left join user_tab_comments c
on t.TABLE_NAME = c.table_name) tmp
on o.TABLE_NAME = tmp.table_name
left join (select cs.table_name,cs.column_name from user_cons_columns cs,
user_constraints uc
where cs.constraint_name=uc.constraint_name
and uc.constraint_type='P'
) const
on (o.COLUMN_NAME=const.column_name and o.table_name=const.table_name)
where o.table_name in ('TEST1')
order by o.table_name , o.SEGMENT_COLUMN_ID