ROWNUM and ROWID

select rownum,zx01,rowid,length(rowid) 长度,
substr(rowid,1,6) 数据对象编号,substr(rowid,7,3) 文件编号,
substr(rowid,10,6) 块编号,substr(rowid,16,6) 行编号,
dbms_rowid.rowid_object(rowid) AS object_id ,
dbms_rowid.rowid_relative_fno(rowid) AS file_id ,
dbms_rowid.rowid_block_number(rowid) AS block_id ,
dbms_rowid.rowid_row_number(rowid) AS num
from zx_file 
where zx03='P050' and substr(zx01,1,1)='0'