SQL Developer: Joining tables from connected SQL Server DB and connected Oracle DB

Question

We are migrating from SQL Server 2005 to Oracle 11G. I have been trying to do an update to a table in Oracle using data stored in a table in SQL Server.

Using SQL Developer, I have completed the following:

1. Created a connection to the Oracle Database

    Created Connection name --> e9_crp Supplied User name and Pass Defined Host Name and SID 

2. I also created a connection to the SQL Server that contains the reference data

    Connection Name --> sql_data User Name and Pass Host and Port 

The connection name used for SQL Server is sql_data

The connection name used for Oracle is e9_crp

The table in SQL Server is in a database my_tmp with owner of dbo and is called tiers ( my_tmp.dbo.tiers ).

In SQL Developer, I can see, select, and view the tiers table. This SQL statement also works using the worksheet when in the sql_data connection:

 select * from [my_tmp].[dbo].[tiers]

Trying to connect to this table when in the e9_crp connection schema, I have been trying to do something like this:

 select * from [sql_data].[my_tmp].[dbo].[tiers]

But this returns an error stating that the tiers table does not exist:

 ORA-00903: invalid table name
 00903. 00000 -  "invalid table name"

Both tables have a unique ID of 'item', so in a perfect world this should work:

 select a.itm, b.tier
 from [e9_crp].[crpdta].[itemmaster] a inner join [sql_data].[my_tmp].[dbo].[tiers] b
     on(a.itm = b.itm)

This is assuming that I use the connection name in the table identifier. BUT, this obviously does not work. What I need to do is be able to join these 2 databases together in a similar fashion as necessary.

How can I use SQL Developer to join these 2 tables? I have tried multiple iterations of table strings for the join but no luck. Any help is appreciated.

Answer 1

Oracle has the concept of a DBLink, and SQL Server has the concept of a Linked Server. Both these features let you query data from two separate databases.

Here's a link with instructions for setting up an Oracle DBLink to a SQL Server DB...

http://www.dba-oracle.com/t_database_link_sql_server_oracle.htm

And here's a link with instructions for setting up a SQL Server Linked Server to an Oracle DB...

http://support.microsoft.com/kb/280106

See also this SO post...

SQL statement joining Oracle and MS SQL Server