Query data between two oracleusers

For example, there are two users in oracle, sysdb and hellodb, and table hello under sysdb. There is a baby table in hellodb. Now I want to use the hellodb User table baby in oracle user sysdb. select * from baby @ link_hellodb www.2cto.com ====================== generally, imp exp is used to back up and import data to the database. However, in some cases, it is necessary to obtain data from two databases flexibly. Here I use the dblink method of or1c.. First, the listener tnsnames. ora file can be connected to the database where you want to create dblink remotely. -- Create dblink MANAGER as the remote database Username password as the remote database password, orcl as the listener connection name www.2cto.com SQL code 1. create database link DDD. REGRESS. RDBMS. DEV. US. ORACLE. COM 2. connect to MANAGER identified by password 3. using 'orcl '; create database link DDD. REGRESS. RDBMS. DEV. US. ORACLE. COM connect to MANAGER identified by password using 'orcl '; in this way, you can connect to the orcl database to obtain the data of each table flexibly. Both databases have tb_demo tables. This is the table to be inserted. The SQL statement for querying data is the same as that for local databases, but @ DDD is added later. REGRESS. RDBMS. DEV. US. ORACLE. COM is equivalent to the remote database connected by dblink. SQL code 1. insert into tb_demo 2. SELECT * FROM tb_demo@DDD.REGRESS.RDBMS.DEV.US.ORACLE.COM 3. where iyear = 2011 4. and imonth = 8 and flag = 0