How can I add/amend/delete columns?

A. Under SQL 7.0 all the above are easily done with standard ANSI "ALTER TABLE" ddl commands. Or they can be done via the gui or supplied stored-procedures.

With SQL 6.5 and below it is only possible to ADD a nullable column - or an IDENTITY column which seems to work even if it's not NULLable. For *any* other change a new table must be created, the data copied across, and the tables renamed around.

Certain 3rd party tools provide a gui interface to do this, that makes it look transparent, however they are really doing all the work described above, so if you make the change to a large table it will take a long time to do the work.

Examples of tools are :-

Microsoft's Visual Database Tools (part of Visual Interdev Enterprise Edition) 
SQL Programmer from
XCase - 
Desktop DBA -
Speed Ferret

Note that there have been reports of Microsoft VDT losing data if you amend columns on a table and SQL does not have enough free-space to complete the task.

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