Alter table interface does not allow me to alter existing columns

DB Visualizer 5.1.1.9

When right click the table from the Tree control on the left, I select Alter to modify the table. While the interface allows me to add new columns and delete existing columns, it does not allow me to alter existing columns. For example, changing a column from support nulls to not supporting nulls, or renaming of a column.

Am I missing something that should be there or is this simply a limitation?

Thanks....

Hi Chris, The Alter Table dialog allows you to change everything that the ALTER TABLE statement for the database supports, and it varies between databases. Some databases do not allow any changes to columns (and/or constraints), only dropping and adding new columns. Others (e.g., JavaDB/Derby) only support changing the size of VARCHAR columns, nothing else. If you tell me which database you are using, I will double-check that it really matches the ALTER TABLE capabilities for that database. Or check the documentation of ALTER TABLE for your database and let us know if we have missed something. Thanks, Hans

Thanks for getting back to me so quickly Hans. I'm working with Sybase ASE version 12.0 presently. I'm reasonably certain that is supports altering of existing columns as I can make those edits via the SQL Commander using the specific SQL syntax provided by Sybase. For example:

ALTER TABLE op_message_info
    MODIFY resource_id NOT NULL
go

This works successfully for me without any exceptions.

Thanks again...

Hi Chris, Thanks for reporting this. You are right: Sybase supports changing column data type and nullability, as well as dropping and adding columns. The Alter Table will be fixed to allow these operations in the next release. Regards, Hans