A Flexible Method of Storing Control Data
By Tony Marston2006-08-29
A flexible approach
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After encountering those disadvantages on more than one occasion I decided on a different and more flexible approach. Instead of a single record containing many values I have each value on its own record, which therefore results in many records. The trick is to store these values in separate records in the database, but to present them to the user in a single screen as if they were separate values on a single record. How is this possible? Read on and learn.
First, let us start with the database structure:
CREATE TABLE `mnu_control` (
`record_id` varchar(16) NOT NULL default '',
`field_id` varchar(32) NOT NULL default '',
`field_value` varchar(255) default NULL,
PRIMARY KEY (`record_id`,`field_id`)
);
| Field ID | Description |
|---|---|
| RECORD_ID | is used to group various records into logical sets. The same table could be
used by multiple applications, so by setting RECORD_ID to the application name each application's data can be kept separate from the other, even if any FIELD_IDs are the same. |
| FIELD_ID | is the name of the field, unqualified, in upper case. |
| FIELD_VALUE | is a string field as its holds any value in display format regardless of the interface definition (number, date, time, boolean, etc) of the source field on the screen. |
Second, build a screen where these records can be displayed and modified:
As you can see this looks like a completely normal screen, which is the whole idea.
Tutorial Pages:
» Introduction
» A flexible approach
» Implementation
» From database to screen
» From screen to database
» Summary
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