Thank you. “clear screen” works.
Can you tell me where I can find the document of abbreviation and their full syntax(not only the clear command but also other commands)? Is that same as sqlplus(http://docs.oracle.com/cd/E11882_01/server.112/e16604/ch_twelve001.htm)?
For SQL*Plus the link you gave is perfect. As you can see there are other things to clear beyond just the screen. For SQL Developer, I'm not sure exactly what level of support we currently provide, or intend to provide in future releases. In general, there is no guarantee of a one-to-one mapping between SQL*PLus and SQL Developer in terms of scripting language support. Find the SQL Developer-specific help document as follows:
Help|Table of Contents|SQL Developer Concepts and Usage|Using the SQL Worksheet|SQL*Plus Statement Supported and Not Supported...
Edited by: Gary Graham on Feb 28, 2012 10:40 AM
Probably requiring "screen" is due to added support for other forms of "clear", perhaps "clear breaks" and so on, for better formatting control.