1. Computing and Information Science 1 Databases START

2. Computing and Information Science 2 What is a Database A database is a collection of data. The data that is collected can be organised for a particular purpose

3. Computing and Information Science 3 Fields NEXT In a database, a field is one piece of information about a person or thing. For example, a database about pupils might have the following fields: Forename Surname Form class Date of birth

4. Computing and Information Science 4 Records NEXT In a database, a record is all the information which relates to one person or thing. So if we look at a school database, all the information about one pupil (forename, surname, date of birth and form class) would be one record in the database. Or, if you look at the phone book, the name, address and telephone number for one person is a record.

5. Computing and Information Science 5 Files NEXT In a database, a file is the entire collection of information. In a school database, this would be the records on all the pupils in the school Or, if you look at the phone book, the entire book would be the file.

6. Computing and Information Science 6 Summary of Structure NEXT If we think of a database as a table of information, then we can identify the structure as:  FIELD is a column  RECORD is a row  FILE is the complete table Fields Records File

7. Computing and Information Science 7 Searching A simple search is a search where you are only looking for one value on one field, e.g. surname = Jones. A complex search is when you are searching for more than one thing -either on different fields (e.g. surname = Jones and forename = Brian), -or for different values in the same field (e.g. surname = Jones or surname = Smith). NEXT

8. Computing and Information Science 8 Search Operators Search operators are used to help specify the records we are searching for. Common examples are: NEXT Equals (=) greater than (>) less than (<) highest or lowest value If you are carrying out a complex search, the search criteria can be linked by using AND or OR. Using AND will find records meeting both criteria only, and using OR will find records meeting either of the criteria specified.

9. Computing and Information Science 9 Sorting Sorting simply means putting the database into order, either ascending (A – Z, 1 – 100) or descending (Z – A, 100 - 1). A sort on one field of the database (e.g. surname or date of birth) is known as a simple sort. NEXT SurnameForename SmithWilliam SmithThomas SmithAbigail ThomsonFred ThomsonJulie

10. Computing and Information Science 10 Sorting NEXT A complex sort is when the database is sorted on more than one field, e.g. sorted in order of surname and forename. This means that if there is more than one record containing the same surname then they will be sorted by forename. SurnameForename SmithAbigail SmithThomas SmithWilliam ThomsonFred ThomsonJulie

11. Computing and Information Science 11 Editing a Database NEXT A database that has been created can be edited by either adding or deleting records or adding or deleting fields. Adding a field allows more data to be stored. For example adding the date of births to a members club database.

12. Computing and Information Science 12 Creating a Database Before creating a database it is very important to design which field names and field types are to be used. NEXT Common field types used are. Text :Any field which contains letters and numbers Number: Any field which contains only numbers Date/Time:Any field which contains a date or time Boolean (Yes/No):A field which contains only two values either true/false or yes/no There are other field types available but these are the most commonly used.

13. Computing and Information Science 13 Creating a Database The length of each field is also important. The database should not have too much room for set aside but also cannot use too little. For example: A database may hold chefs names, including Ken Hom and Marco Pierre White. For the forename field we will need to have at least 5 characters for the chefs given (Ken and Marco) but there may be chefs with longer forenames so we should perhaps set aside 10 characters for forename. For the surname field we will need to have at least 12 characters for the chefs given (Hom and Pierre White, a space is counted as a character) but there may be chefs with longer surnames so we perhaps should set aside 20 characters. NEXT

14. Computing and Information Science 14 Altering Output Format NEXT You can alter the output format of your database by choosing which fields/records will appear either on the monitor or on a printout, for example:

15. Computing and Information Science 15 Reporting One of the most powerful features of database packages is the reporting feature. This allows you to use any part of your database to create a printed report on a specific area. Reporting allows you to:  Select which fields you want to appear  Select which records you want to appear  Select the order in which the records appear  Include calculations on the data  Add text and formatting to the such as report headings, underlining, page numbering and so on. NEXT

16. Computing and Information Science 16 Creating a graphic field Creating a graphics field allows pictures to be included into your database. This is an important feature, making databases more informative. For example the passport office, police and customs would all make use of databases like these. NEXT

17. Computing and Information Science 17 Creating a Computed Field A computed field is a field type which involves a calculation. The data the field contains is calculated using the values of data in other fields of the record. For example a record might consist of 4 fields. Name of product:Text Cost Price:Number VAT:Number Total Cost:Calculated (Cost Price + VAT) NEXT

18. Computing and Information Science 18 Calculating Storage Requirements Example Here is the design for a simple school database which contains 300 records. NEXT The storage required for one record: 20 + 20 + 4 + 40 + 15 = 99 bytes

19. Computing and Information Science 19 Calculating Storage Requirements Example There are 300 records in the database, so the total storage space required is: 99 x 300 = 29 700 bytes We can convert this to kilobytes by simply dividing the total by 1024: 29 700/1024 = 29kb NEXT

20. Computing and Information Science 20 Multimedia Databases Many CD-Roms contain information stored in a database. For example, a multimedia encyclopaedia is essentially a database of articles. These databases usually have a search tool that allows you to find articles containing keywords. Find articles including the phrase “World War One” It is also possible to do more complex searches involving several keywords using AND, OR and NOT Find articles including the words “World War One” OR “First World War” It is also possible to search web pages in the same way using a Search Engine such as google or altavista

21. Computing and Information Science 21 Data Protection Act (1998) The Data Protection Act (1998) became law on 1st March 2000. It governs the processing and storage of personal information held by organisations/businesses/schools on computer. It also governs some paper records. If an organisation is going to store data about people, it has to register this intention with the Data Protection Commissioner, who keeps a public register. This register stores the name and address of the data controller, and a description of the processing being carried out. Individuals can consult the register to find out what processing is being carried out. The data subject must also be aware of the data being stored and for what purpose. NEXT

22. Computing and Information Science 22 Data Protection Act - Principles The following definitions apply under the Data Protection Act: NEXT Data Subject – The person whom the information is about. Data Controller – The organisation collecting and controlling personal information Data User – Someone authorised by the Data Controller (eg an employee) to use the personal information

23. Computing and Information Science 23 Data Protection Act - Principles Personal information must be:-  Obtained and used fairly and lawfully.  Only used for specified purposes (the purpose must be specified prior to obtaining the data).  Adequate, relevant and not excessive.  Accurate.  Processed in accordance with the data subject’s rights.  Secure. NEXT And must not be:-  Kept longer than necessary,  Transferred to countries without adequate protection. There are 8 data protection principles:

24. Computing and Information Science 24 NEXT To see personal information being held about you (right of subject access). To prevent processing likely to cause substantial damage or distress (not in all cases). To prevent processing for the purposes of direct marketing. To take action to rectify, block, erase or destroy inaccurate data. To ask Commissioner to assess whether the Act has been contravened. To take action for compensation if damage or distress is caused. Under the Data Protection Act, a Data Subject has the following rights:- Data Protection Act - Definitions

25. Computing and Information Science 25 Computer Misuse Act (1990) The Computer Misuse Act (1990) was made to try to prevent unauthorised access to computers, otherwise known as hacking. Under the Act, it is illegal to: Gain unauthorised access to a computer, its programs and its data; Gain unauthorised access to a computer, its programs and its data with the intent to commit a further offence; Modify computer material after gaining unauthorised access - this includes hardware, programs and data. NEXT

26. Computing and Information Science 26 Copyright, Designs & Patents Act (1988 ) This act gives people certain rights over work they do. It covers books, music, films and computer programs among other things. The act makes it illegal to Create copies of work (e.g. pirate software, copy music CDs and DVDs) Use illegally copied materials (e.g. listening to pirated CDs)