MODIFY STRUCTURE
Class
Terminal Developer Development Tools
Purpose
Full screen modification of a table structure through a form
Syntax
MODIFY STRUCTURE [<dbf filename> | (<expC>)]
See Also
COPY STRUCTURE EXTENDED, CREATE, CREATE FROM, CREATE TABLE, SET DESCRIPTIONS, SET HIDDENFIELD, SET MCONFIRM, SET RELATION
Description
The MODIFY STRUCTURE command is a full screen command used to modify the structure of table <dbf filename>. The filename can be substituted with a <expC>, enclosed in round brackets, which returns a valid filename. If no <dbf filename> is specified the command will work in the current workarea. If no table is open in the current workarea, you will be prompted for a filename. If no file extension is specified, then ".dbf" will be used.
If the command MCONFIRM is set OFF, the MODIFY STRUCTURE menu bar operates as pulldown menus.
When a table structure is modified, a backup of the old table, with the file name extension '.bak' is created.
When modifying a table structure, the table is automatically reloaded. Any changes to the structure of the table cause records from the old table to be appended into the new table. Since the APPEND command only copies fields which exist in both tables, and are of the same data type, you should use MODIFY STRUCTURE twice if you want to change a field name as well as the field width. APPEND triggers defined in the data dictionary will be called for each record as the table is reloaded after a MODIFY STRUCTURE operation. When the width of a character field is increased, the remainder of the field will be padded with blanks. When the width of a character field is decreased, the field will be truncated to the new width.
Changes of incompatible data types cause the old field contents to be discarded.( e.g. changing from a Date field to a Numeric field.)
See the CREATE command for more details.
Example
use events modify structure
Products
Recital Terminal Developer
