19. Database Solutions Flashcards
(18 cards)
Cascade update related records
If you select this option and you make a change (update) to the primary key value of a table that is at the one end of a one-to-many relationship,
then Access will also update all the foreign key values in related records in the table at the ‘many’ end.
Cascade delete related records
if you delete a record at the ‘one’ end of a one-to-many relationship it will also delete related records in the table at the ‘many’ end.
FILTERS
What are the filter options
Sort.
To sort the data by the chosen field, use the ascending (A-Z) or descending (Z-A) buttons.
Number filters.
Clicking on this option will pop another menu out from where you can choose comparison filters such as ‘equal to, ‘greater than’, ‘less than, etc. When you choose the filter you want it will then pop a dialogue onto the screen asking you the value that you want the comparison made with.
Individual values.
All the different individual values in the field are listed here, and you can click in the check boxes next to the value(s) you want to filter.
query criteria,
Date().
This represents the current date,
Comparison operators.
You can use ‘<’ or ‘>’ to find any records with a date before or after the one entered
Between.
You can use between with two dates to find any records with dates between the given dates,
for example between 1/1/24 and 20/1/24. Access will automatically add # symbols before and after the dates.
Date Part.
You can find records that match a given month by using the DatePart function.
For example DatePart(“m”.[order_date])=2 will find any order_date records in the month of February: the “m” tells the function to look for months and the ‘2’ sets it to February.
This criterion: DatePart(“yyyy”.[order_date])=2024 would find all the order_dates in 2024.
Intuitive layout. examples
Make sure all fields and buttons are clearly labelled.
Make it clear which data entry fields are mandatory and which are optional. This can be done by placing an asterisk (*) next to the mandatory ones.
Have a visual hierarchy with the most important things at the top of the form. Use text size to indicate importance, with more important field information in a larger size font.
Where you have menus that can take users to other forms, always provide a way back to the menu (typically with a back button).
Provide a way to cancel an operation.
Features of good design.
Use a simple colour scheme, with just a few colours - two or maybe three complementary colours that are not too bright.
As with colours, use a very limited number of fonts, probably the same typeface for all the forms, although you can vary the size.
Be consistent in your layout when you have several forms. Aim for a ‘house style’ where the same formatting and layout is used in all the forms in an application.
Make sure that the layout is neat, with fields aligned to each other and labels aligned with the fields that they belong to.
TESTING THE SOLUTION
Testing is important because:
- You need to check that the application you have created meets the requirements that were
defined before the development started.
In other words, does it do what it is supposed to do? - You need to confirm that the database application you have created works as it should.
Does it produce the correct results?
This is particularly important where calculations are
being done. - You need to test that all the features and functions of the application work as they should.
For example, do all the buttons produce the expected result?
EVALUATING A DATABASE
the number of things that you need
to consider.
Is it fit for purpose?
Is it easy to use?
How easy is it to maintain the database?
Enhancing a database.
Q: What must you check when evaluating your database against a scenario?
A: Whether the requirements listed in the scenario have been met by what you have produced.
Q: Why is it difficult for the database creator to judge ease of use?
A: Because creators are familiar with the system, whereas users may not be IT professionals.
Q: How can you get feedback on your user interface design?
A: Show it to peers or others who are not IT experts to get their opinions.
Q: What is a major limitation of Microsoft Access?
A: It lacks features for multi-user environments and web-based interfaces.
Q: What affects the ease of maintenance of an Access database?
A: The quality and detail of the design documentation.
Q: Why is design documentation important for maintenance?
A: It helps others understand how the database was designed and created.
Q: Give examples of simple database improvements.
Adding clearer instructions
rearranging fields on a form
rewording error messages.
