Techniques for Changing Table Columns
The examples here describe how to change table columns, including:
• Renaming a column
• Inserting a column
• Changing the data type of a column
There are no direct equivalents for changing columns in VDBA or in a single SQL statement.
Note: Renaming a column in a table or changing its data type does not change anything else that is dependent on the column. You need to update any objects, such as reports, forms, and programs, which are dependent on the old column name or data type. In addition, all of the procedures shown here require that you drop the original table, at which point certain other dependent objects, such as integrities, views, indexes, and grants, are also dropped. You must recreate these objects.
Important! We recommend that you back up your tables before changing them. If a problem occurs, you can then restore the original table and repeat the procedure. For additional information, see the chapter “Performing Backup and Recovery.”