Make Mileage
Model Registration
Price Fuel
Number of owners Body type
Top Speed Colour
2)
The research I carried out to produce my data capture sheet, which shows details of cars, was from two different sources. One being I.T and the other non-I.T. Using I.T I could access the Internet, which would enable me to visit various sites and look up car details. Some of the sites I used are mentioned below:
From the sites I accessed details of cars through which I was able to design a data capture sheet and place the details in appropriate ways. At certain stages I also had to use search engines, these were useful and found specific information I required. I was most successful when I used the autotrader site because it matched my attributes in the sense that it had all the data I needed. Here is a snapshot of a page that I acquired data from:
This is how I stored the data from the above web page into my database:
As for the research I did without I.T, it mainly revolved around magazines and newspapers. Although I used newspapers I was more successful with car magazines and ‘The Auto Trader’.
Some magazines I used were:
- Auto pages
- Car Fusion
- Cars4All
From these I could easily find car details and place them into my data capture sheet.
Here is a page from the auto trader magazine:
This is a view of how I used the data efficiently in my database:
Overall my research was evenly done between I.T and non-I.T sources.
I choose text for the data type for the model of a car because it covers both numbers and text, which are required in ,many of the cars
E.g. BMW 3Series
As the validation for a car price I used computer language to ensure negative or any invalid data isn’t accepted.
I also ensured all the field sizes were big enough, and at the same time not too big.
The reason for this user guide is to show step by step development of my database. I will describe certain things I did and give evidence by using print screens.
- To start with I went into the Microsoft access package and opened a blank database, and then I named the database and gave it a file location.
- Following this a screen appeared which gave me the following options:
- Tables
- Queries
- Reports
- Forms
From these I choose to make a table.
- Now I had to fill the table in with the appropriate headings and data.
- Once I had filled in the table I went to view and selected ‘design database view’.
This is the screen I then saw:
- On seeing the design view I was able to enter field sizes, field types and validation text and rules.
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Following this I returned to my database table by selecting the view button in the top left corner.
- Now my database was created and looked like th
A verification check is visually checking the data for mistakes and errors. This is to ensure that any error you may have made whilst entering the data is changed. If a verification check is not done it can result in the whole piece of work being useless, for instance if I made a mistake in my database or missed out anything it would end up ruining the whole database. Humans can make mistakes and not notice them at all, therefore a verification check is a necessity.
I did come to realise the importance of a verification check once I saw the number of mistakes I had made.
Here are a few mistakes I made:
-
In the process of filling in the colour of a car I spelt Silver incorrectly, this wasn’t because I could not spell the word but instead was a human error.
After realising this mistake I corrected it:
2)
In the highlighted cell I had not entered the car model, and soon after noticing I entered the appropriate model.
Validation is the name given to checks a computer can carry out when data is input. There are a number of checks that come under this category:
- Presence Check-Whether the data is entered or not.
- Character Count-There should be a certain number of characters.
- Range Check-The data is in between particular ranges.
- Picture Check-Whether the entered data was expected or not.
In my database I used validation rules which enable data to be accurate.
For example, a validation rule that stated a car can only cost up to £80 000, would ensure no price would exceed £80 000.
In my database I have included two validation rules. The first one is for the number of car owners, which had to be from 0 up to 5 this meant it was a range check. As the validation rule I entered “>=0 AND <5”. As the validation text I choose to type “Enter a positive number under 5”.
To test my validation rule I entered a number out of that range and saw the following:
The validation text I had typed came up, therefore the validation rule was correct.
The other validation rule I used was a presence check, to make sure the valid data was entered. It was for the colour of the car, as the validation rule I typed “Is Not Null” and for the validation text “Enter valid colour”.
Here is a print screen testing the rule:
Queries are used to retrieve data from one or more tables and display the results in a datasheet where you can update the records.
To understand how to create queries I searched on the Internet for a user guide, which I successfully found. Here are the step by step actions I followed:
1)
2)
3)
Once I knew how to create a query I was able to carry out my own queries.
I will show two queries I have created:
1)
Customer Question-Do you have a Diesel Nissan Primera?
Query Design-
Query Results-
2)
Customer Question-Do you have a Smart Car in White for under £10000?
Query Design-
Query Results-
By making queries I can be search for data and also add data easily.
To do my project I had to select a software, which would be most useful for me and my task. The software I choose was Microsoft Access because it consisted of the features I needed.
Microsoft Access was useful to me because in order to create a database I needed something that could store/handle large amounts of data. Using Access I could also answer queries and within seconds show results. This is a search facility, which isn’t available on other softwares such as Excel.
Overall it also has a very user-friendly look.
Comparison:
I will make a comparison between Access and Excel for my given task. Access was more suitable for me because I could create a table and give it validation rules and checks. I would not be able to create validations on Excel. Access has also an additional feature than excel because it is able to locate specific queries in the data table. This is useful for update of data, which can be difficult in Excel.
Overall I have come to realise that Access is more suitable for data handling and excel is more suitable for data modelling.
For the project I was doing I needed to have appropriate attributes to show the data. I was able to select certain attributes, by their necessities. Following is a list of attributes some of which I have included and some not. Each has a reason for its selection:
- Make-Always required to refer to cars
- Model-Which year it was made in
- Colour-Needed for customer preferences
- Top Speed-Not needed for usual buyers
- Age-Isn’t as useful as number of owners
- Doors-Determines whether a car is a family car, sports car or a 4X4, but not the first thing considered by customers
- Ranking-No need for comparison with other cars
- Mileage-Number of miles car is run (alternative to age)
- Fuel Type-Very important for most buyers
- Prices-Cost for the car
- Number of owner-Alternative for age
From the above I selected the following because they were most suitable:
I was able to finalise the attribute lists by asking an established car dealer, the most appropriate headings to the customer’s suitability. In order to this I formed a questionnaire.
Why forms are created
Why its easier to enter data
