Changing a column

Use the Change Column notebook to modify a column for the table that you're creating or altering.

These steps are part of the larger tasks of creating a table and altering a table. When you complete these steps, return to either creating a table or altering a table.

To modify an existing column:

1. In the Change Column notebook, change the fields and controls that you want to modify.

   If you change the column name and you are using this column in a primary key, a unique key, or a foreign key, you must go back and revise the definitions for those keys.

   Restrictions: If you are changing a column that has already been committed in the table, the only fields that you can modify are:

   • On the General page, the Comment field. The comment can be from 1 to 254 characters long.
   • On the Built-in Type page, the Length field for a VARCHAR column. For a VARCHAR column, the maximum length you can have depends on whether or not you have an edit procedure and what the page size is for the table. If there is no edit procedure, the maximum VARCHAR length is:
     • 4048, for a 4 KB page size.
     • 8130, for a 8 KB page size.
     • 16322, for a 16 KB page size.
     • 32706, for a 32 KB page size.
     If there is an edit procedure, the maximum VARCHAR length is:
     • 4038, for a 4 KB page size.
     • 8120, for a 8 KB page size.
     • 16312, for a 16 KB page size.
     • 32696, for a 32 KB page size.

2. Click OK to make the changes you specified for the column and close the Change Column notebook.

Depending on the task that you were doing when you changed this column, return to either creating a table or altering a table.