2. What is Data? Data are “raw” facts 23 Red 1.8 All of the above are examples of data items When the data is put in a context it becomes information 23 years old The colour is red The height is 1.8m
3. Use of Data The storage and processing of data is one of the major uses of IT in the world. There are many types of programmesavailable that can process data but the two main types are: Databases Spreadsheets There are several different data types that can be stored and processed in these programes.
11. OLE Objects OLE = Object Linking and Embedding These can be a range of objects such as: Sound Video Images Text This data type enables you to create objects in one application and link i.e. Create a photo of a product to place in an online catalog.
12. Why use databases? Databases can store very large numbers of records efficiently (they take up little space) It is very easy and quick to find information. It is easy to add new data and to edit or delete old data. Data can be searched easily (eg, 'find all Ford cars'). Data can be sorted easily, for example into 'date first registered' order.
13. Why use databases? Data can be taken into other applications, for example a mail-merge letter to a customer. More than one person can access the same database at the same time - multi-access. Security may be better than in paper files. Databases can be used to store information entered into web pages. Most interactive websites: Internet banking Online auctions Discussion forums Social networking sites Online games sites Have a database as the “back end” that stores the information and a web page as the “front end” that the user sees
14. Storing data In a database information is stored in fields A field can be thought of as a “box” that holds the data Bob Smith First name Family name Smith Bob
15. Database file All the information about one person “Bob Smith” is a record
17. MS Access: Tables Data in MS Access is typed into fields. Fields are stored in Tables. Below is a screenshot of a table showing the fields and their data types
18. MS Access: Forms Typing data into tables can be confusing to a user so we can use a Form to make a user “friendly interface”. Below is an order form for a Pizza Company database. The form makes it look more like a “proper programme”.
19. MS Access: Queries To process data in a databse we use a query Queries can perform several different tasks in a database: Search for data Sort data Perform calculations Delete data Update data SQL = structured query language
20. MS Access: Queries A query that sorts a list of Pizzas by name A query that searches for an invoice and also has a calculation to generate the total price.
21. MS Access: Reports Reports are printouts. Data from the database is used to generate a report. Reports can be printed from tables or from the processed data by creating a report based on a query. Other calculations e.g. adding up totals can be done on the report.
23. Relational databases In a relational database data are stored in fields in tables The tables are connected with common linked fields (relationship)
24. Relational databases This means that each piece of data needs only be entered once but is available in the entire database This avoids the issue of data redundancy which might cause incorrect versions of data to be present Multiple spellings of a persons name Errors in other important data like phone numbers or bank details
