Oracle DatabaseLink cross database connection

Oracle DatabaseLink Cross database operations

I have such a need in my daily work , To build a test environment , You need to import some tables and data from the development library into the test library . Or use some tables in the development library in the test library , The data of the view . At first glance, there are many implementation methods for this requirement , At least... Can be used Oracle Import and export of . This can certainly be achieved , But the feeling is quite low, Let's take a look at a tall and fashionable way , Use Oracle Medium DATABASE LINK.

DATABASE LINK seeing the name of a thing one thinks of its function , Is the connection to the database , The function is to connect to other databases , And convenient operation of other data . But from this point of view , Is it very powerful .DATABASE LINK There are two kinds of , One is public , One is private , Here we mainly introduce the public .

1. establish DATABASE LINK （ Remote connection Library ）

create public database link DATABASE_LINK_NAME
  connect to CONNECT_DATABASE_USER identified by "CONNECT_DATABASE_PASSWORD"
  using '(DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = CONNECT_ORACLE_SERVER)(PORT = CONNECT_ORACLE_SERVER_PORT))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = CONNECT_ORACLE_SERVICE_NAME)
    )
  )';

For example, I want to connect 192.168.101.111 Under this server The port number is 1521 Of orcl Database instance . User name is scott The password is tiger,database link The name is scottdl

create public database link scottdl
  connect to scott identified by "tiger"
  using '(DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.101.111)(PORT = 1521)) ) (CONNECT_DATA = (SERVICE_NAME = orcl) ) )';

This creates a DATABASE LINK

-- see link
select * from dba_db_links;

 Delete DATABASE LINK
drop public database link scottdl;

2. Use DATABASE LINK

I want to put emp The data table , Sync to my database , You can do that

create table test as (select * from EMP @scottdl );

Direct query is also possible

select * from EMP @scottdl（link name ）

newly build DATABASE LINK Option two

1. open PL/SQL Tool NEW

2. Fill in the configuration information
   
3. After creation, you can view it in the folder or sql Inquire about

-- see link
select * from dba_db_links;

Finally, you can do what you want , Isn't that easy ！