Designing a Database

Transcription

1 Designing a Database Databases: Concepts of Database Design

2 1 - William Gladstone s Diaries (5 minutes max) William Gladstone (Prime Minister during the period ) kept a diary all his life, recording every person he met. He met some people many times, others only once. Most of them associated with one or other political party or group. The diaries have now been published and the editor wants to produce a final index volume, giving details about each person mentioned and the date/s when Gladstone met them, as well as their political affiliations. She also wants to be able to find all the people whom he saw on a particular day, for checking. Discuss in your group the fields that may be needed. Organise the fields into groups which belong together, and allocate them to tables. For each field in a table, decide on the data type (text, number, date, yes/no etc.). 2 - Archaeological Sites and Swords An archaeologist is working on the swords found at various burial sites. She wants to record the details of the swords and compare them with the age of the site and its location. A map grid reference can be expressed in terms of Eastings and Northings e.g. 123 (easting) 456 (northing). Design a database to store this information. Sketch out the tables needed, and the fields to be included in each. Note any assumptions or simplifications you agree on.

3 3 - Fossil Species Survey A collector visits 10 different beaches, looking for 35 species of fossil. On each visit, he records how many of each species he finds at each beach. Can you suggest a better structure than that shown? Name some better tables and fields and show how they are related. 4 - Apprentice Doctors A hospital archive lists the apprentice doctors who worked at each local hospital in the th centuries. An apprentice doctor would be supervised by a more experienced practitioner for a specified date period. Draw a design for a database where these records could be analysed. Think about the fields that would be relevant to collect, and how they could be organised into tables. Show how the tables should be related to one another. Make a note of any assumptions or simplifications that you make.

4 5 Lending Library A private lending library operated in Victorian Kensington. To join the library, a person had to register and pay a membership fee (1 shilling for 1 month, 5s for 6 months or 7s for a year). The maximum time a book could be borrowed was 7 days. Design a database to analyse the details of individual members, details of each book stocked and who borrowed each one. If you have time, make provision in your design to record books that were returned after the due date, along with the fines levied. How could you include details of the author/s of the books? 5 Lending Library A private lending library operated in Victorian Kensington. To join the library, a person had to register and pay a membership fee (1 shilling for 1 month, 5s for 6 months or 7s for a year). The maximum time a book could be borrowed was 7 days. Design a database to analyse the details of individual members, details of each book stocked and who borrowed each one. If you have time, make provision in your design to record books that were returned after the due date, along with the fines levied. How could you include details of the author/s of the books?

5 Group tasks Model Answers Here are some possible ways of answering the group tasks. They are not definitive: the best design is the one that fits well with the practicalities of your situation. The purpose of the activity is to help you practice analysing a scenario and designing a sensible way of managing the data. You may come up with something quite different!

6 1. Gladstone Diaries Question William Gladstone (Prime Minister during the period ) kept a diary all his life, recording every person he met. He met some people many times, others only once. Most of them associated with one or other political party or group. The diaries have now been published and the editor wants to produce a final index volume, giving details about each person mentioned and the date/s when Gladstone met them, as well as their political affiliations. She also wants to be able to find all the people whom he saw on a particular day, for checking. Discuss in your group the fields that may be needed. Organise the fields into groups which belong together, and allocate them to tables. For each field in a table, decide on the data type (text, number, date, yes/no etc.). A Possible Answer

7 2. Archaeological Sites and Swords Question Question An archaeologist is working on the swords found at various burial sites. She wants to record the details of the swords and compare them with the age of the site and its location. A map grid reference can be expressed in terms of Eastings and Northings e.g. 123 (easting) 456 (northing). Design a database to store this information. Sketch out the tables needed, and the fields to be included in each. Note any assumptions or simplifications you agree on. A Possible Answer

8 3. Fossil Species Survey Question A collector visits 10 different beaches, looking for 35 species of fossil. On each visit, he records how many of each species he finds at each beach. Can you suggest a better structure than that shown? Name some better tables and fields and show how they are related. A Possible Answer

9 4. Apprentice Doctors Question A hospital archive lists the apprentice doctors who worked at each local hospital in the th centuries. An apprentice doctor would be supervised by a more experienced practitioner for a specified date period. Draw a design for a database where these records could be analysed. Think about the fields that would be relevant to collect, and how they could be organised into tables. Show how the tables should be related to one another. Make a note of any assumptions or simplifications that you make. A Possible Answer

10 5. Lending Library Question A private lending library operated in Victorian Kensington. To join the library, a person had to register and pay a membership fee (1 shilling for 1 month, 5s for 6 months or 7s for a year). The maximum time a book could be borrowed was 7 days. Design a database to analyse the details of individual members, details of each book stocked and who borrowed each one. If you have time, make provision in your design to record books that were returned after the due date, along with the fines levied. How could you include details of the author/s of the books? A Possible Answer