Oracle cross database query table data (between different database connection is established)

Created by Marydon on 2018-04-14 12:02

1. scenario demonstrates

　　When you need to access data from database B A library, it is necessary to connect these two libraries;

　　How the two databases to achieve interoperability, the oracle can be achieved through the establishment of DBLINK.

2. Solution

　　2018/12/05

　　Step 1: Create DBLINK

　　Premise: To establish two IP communications database must implement access to each other.

　　Method 1: Use plsql achieve

　　Select the "database link" -> right click -> New

 

 

 

　　Name: The name DBLINK created through which to access the complete library of B;

　　B configuration required to connect the library user name, password, and database address

 

 

 

　　Second way: through sql realization

　　Method One: recommended

Create  Database Link DATABASE_LINK_TEST - database alias 
  Connect to DB_TEST IDENTIFIED by DB_TEST - on the application of a username and password 
  the using ' 127.0.0.1:1521/ORCL ' ; - Name: port number / database instance

　　Method Two:

　　template

the Create  Database Link just a name 
  Connect to the username IDENTIFIED by password 
  a using ' (the DESCRIPTION =                        
    (ADDRESS_LIST = 
      (ADDRESS = (PROTOCOL = TCP) (HOST = domain) (PORT = port number)) 
    ) 
    (CONNECT_DATA = 
      (SERVICE_NAME = database examples name) 
    ) 
  ) ' ;

For example:

- the Create Database Link 
the Create  Database Link DATABASE_LINK_TEST - a custom database name to connect 
  Connect to username IDENTIFIED by password   - username and password 
  a using ' (the DESCRIPTION = - Database Connection: domain name, port number, database instance    
    (ADDRESS_LIST = 
      ( = ADDRESS (= the PROTOCOL the TCP) (the HOST = 127.0.0.1) (PORT = 1521)) 
    ) 
    (the CONNECT_DATA = 
      (SERVICE_NAME = ORCL) 
    ) 
  ) ' ;　

　　Step two: Call mode

　　B database alias name of the database table B @ connection

select * from BASE_TEST@DATABASE_LINK_TEST