select * from
(select name,time,price,good,null address,null store,null belong,null class,null from,null to from table1
union all
select name,time,null price,null good,address,store,null belong,null class,null from,null to from table2
union all
select name,time,null price,null good,null address,null store,belong,class,null from,null to from table3
union all
select name,time,null price,null good,null address,null store,null belong,null class,from,to from table4)
order by time desc,name
(select name,time,price,good,null address,null store,null belong,null class,null from,null to from table1
union all
select name,time,null price,null good,address,store,null belong,null class,null from,null to from table2
union all
select name,time,null price,null good,null address,null store,belong,class,null from,null to from table3
union all
select name,time,null price,null good,null address,null store,null belong,null class,from,to from table4)
order by time desc,name
price 和null price是不同的datatype
============================================
ERROR at line 1:
ORA-01790: expression must have same datatype as corresponding expression
to_date('19000101','yyyymmdd')