Connect to the Oracle user or schema (that will be the owner of the DB Link). In the Object Explorer | go to the DB Links section | use the “Create a Database Link” icon | fill out the fields | click on Show Script (adjust the window size if this button is hidden) | examine the script | click on Execute to run the create script.
Example query code that uses a DB Link:
SELECT * FROM emp_table@DBLINK_NAME;
