oracle查询所有表的所有字段
select TABLE_NAME ,COLUMN_NAME
from user_tab_columns
where Table_Name IN (
select table_name from user_tables where ( table_name like 'xxx%' OR table_name like 'xxx%') -- 查询所有这里不写where
) AND DATA_TYPE LIKE '%VARCHAR%'; -- 查询所有这里不写where