建立DBLINK select a.column_name from user_tab_columns a where a.table_name='A' and not exists (select 1 from user_tab_columns@dblinkA where a.column_name=b.column_name and b.table_name='A")
分别查出比原库多出来的列和少了的列然后再连接 建立DBLINK select a.column_name,'a' from user_tab_columns a where a.table_name='A' and not exists (select 1 from user_tab_columns@dblinkA where a.column_name=b.column_name and b.table_name='A") union all select a.column_name,'b' from user_tab_columns@dblinkA a where a.table_name='A' and not exists (select 1 from user_tab_columns where a.column_name=b.column_name and b.table_name='A")
1.在其中一个库中建立链接数据库指向另一个 2.查询 select a.column_name,'a' from user_tab_columns a where a.table_name='A' and not exists (select 1 from user_tab_columns@dblinkA where a.column_name=b.column_name and b.table_name='A") union all select a.column_name,'b' from user_tab_columns@dblinkA a where a.table_name='A' and not exists (select 1 from user_tab_columns where a.column_name=b.column_name and b.table_name='A")
select a.column_name from user_tab_columns a where a.table_name='A' and not exists
(select 1 from user_tab_columns@dblinkA where a.column_name=b.column_name
and b.table_name='A")
建立DBLINK
select a.column_name,'a' from user_tab_columns a where a.table_name='A' and not exists
(select 1 from user_tab_columns@dblinkA where a.column_name=b.column_name
and b.table_name='A")
union all
select a.column_name,'b' from user_tab_columns@dblinkA a where a.table_name='A' and not exists
(select 1 from user_tab_columns where a.column_name=b.column_name
and b.table_name='A")
2.查询
select a.column_name,'a' from user_tab_columns a where a.table_name='A' and not exists
(select 1 from user_tab_columns@dblinkA where a.column_name=b.column_name
and b.table_name='A")
union all
select a.column_name,'b' from user_tab_columns@dblinkA a where a.table_name='A' and not exists
(select 1 from user_tab_columns where a.column_name=b.column_name
and b.table_name='A")
我就是要比较两个表中有哪些列不同,比如说表A比表B多了几列,或是表B比表A多了几列