DATABASE CHOICES
Access Forms - Bound or Unbound?
Microsoft Access is designed for rapid application development. A form wizard allows
fast and easy application development using Bound forms. The Bound form requires
little or no programming, and is ideal for the amateur programmer.
Unbound forms require Visual Basic code to retrieve and update records. The Microsoft
Access form can have a mixture of fields that are Bound or Unbound.
The Bound Form
The Bound form has bound fields that are linked directly to the database. Any changes
made to a bound field are immediately updated in the database.
The features of the Bound form include:
- Quick set up time
- Find, Filter or Sort facility
- Record number and a navigation bar
- Spell Checking
- Selecting, adding, deleting or modifying Records
The drawbacks of the Bound Form
Access applications have a habit of growing in size and complexity. In order to
add features to the Bound form, the logic can soon become complex. Some problems:
- The default behaviour of Access may be unacceptable – such as automatically
saving fields or records
- There are performance issues when manipulating data from the BackEnd Database
- There is the need to explicitly control record locking
The Unbound Form
The Unbound form is often a better solution. It is needed for greater efficiency,
to extend user numbers and to provide better control of the application. The Unbound
form involves the use of VBA (Visual Basic for Applications) and ADO (ActiveX Data
Objects).
The advantages of the Unbound form are:
- Greater control in reading and writing of records
- Records are updated only when all fields are valid
- Better error handling
- Efficiency in accessing records
- Elimination of concurrency issues
- Control of saving and deleting records
- Data integrity.
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