• Relationships are evaluated in both directions to determine what type of relationship exists (e.g. “one friend may have many telephones”, and “one telephone belongs to a single friend”)
An entity relationship diagram is a data modeling technique that creates a graphical representation of the entities, and the relationships between entities, within an or information system. Entity relationship diagrams are abstractions of the real world, which simplify the problem to be solved while retaining its essential features.
The whole purpose of drawing entity diagrams is that they enable the systems analyst to analyze the data, and once this is done, design the database and implement it. Drawing these diagrams brings to the attention of the analyst any problems with many-to-many relationships, and so they can ensure their final data model is valid.
The database contains three main entities, CUSTOMER, PAYMENTS, and ITEM
3.4 Overall System Design
Tables
In this section it will be showing each table with each description.
TblCustomers
TblProducts
TblOrders
Input
Forms – backgrounds
The use of forms is very important as it allows many user-friendly solutions within the actual system when the customer or employee is using it. Forms are useful in a database as it can create a data-entry form to enter data into a table. Also it can enable the user to create a custom dialog box to accept user input and then carry out an action. Another reason why forms are important within a database application is because the user is able to create a switchboard to open other forms or reports. Forms allow you to focus on one record at a time with all the data pleasantly laid out on the screen. You can build several forms for different groups of users to reflect their different needs. You can use the form to view the contents of tables or the results of queries.
One form can be used to enter data into several tables. Forms automatically use the relationships built into your database.
Input Forms
FrmCustomers
FrmCustomers
Reports/other
A report is an effective way to present your data in a printed format. Because you have control over the size and appearance of everything on a report, you can display the information the way you want to see it. Most of the information in a report comes from an underlying table, query, or SQL statement, which is the source of the report's data. Other information in the report is stored in the report's design.
Reports/other out put -DRAW BY HAND
Mail Merge
The mail merge option will allow the user to load up word directly from Access, and specify which of the several queries should be used as the source of the data. It is a feature supported by many word processors that enables you to generate form letters. For the user to use a mail-merge system, you first store a set of information, like a list of names and addresses, in one file. In another file, you write a letter, substituting special symbols in place of names and addresses (or whatever other information will come from the first file). The power and flexibility of mail merge systems varies considerably from one word processor to another. Some word processors support a full set of logical operators that enable you to specify certain conditions under which information should be merged. Also, some merge systems allow you to merge data from several files at once.
Queries
Queries are used to view, change, and analyze data in different ways. You can also use them as the source of records for forms, reports, and data access pages. The most common type of query is a select query. A select query retrieves data from one or more tables by using criteria you specify and then displays it in the order you want.
Menu Design
Security
There will be a password attached to the database so it can only be accessible to anyone that knows that certain password. There will be no security levels when entering the main database, but in tables such as Customers details there will be another password as it would be against the data protection act if other users can edit some of the customers details. There will also have to be a watch on if there is any personal information on anyone being used for any unreasonable uses.
Testing
Testing will be used to check whether all the aspects within the database are correct. Things such as command buttons (print, exit etc) will be tested. Logical testing will be used to test every aspect of each form, report and query as soon as it is implemented, using valid, invalid and extreme data. Functional testing is going to be where each menu item will be tested in turn to make sure that none of the functions have been missed out. The next type of testing that I will be carrying out is going to be systems testing. This is when the system is finished; all of the range of tests will be carried again to ensure that no other errors have been entered. Recovery testing will also be used in the database. The computer will be restarted while the database is open to ensure the data is not lost or corrupted incase there is a power failure. The last type of testing that will be carried throughout the system is acceptance testing. The user will be asked to test the capabilities of the system to make sure that all of the required functions are present and working as expected.
Test Plan
