Simple databases

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Introduction

Previously in this module we have examined why it's important to design digital resources for real people, rather than for some imaginary average person. You have used simple, low cost, rapid paper-based sketching techniques for finding out what users think about designs and for capturing their ideas. We have also looked at issues surrounding digital assets: how to capture, store, and protect them and how to make them available. Now we are going to turn our attention to how information can be organised to make it easier to search and analyse when we have got a lot of it. Database systems are essentially nothing more than computerised record-keeping systems that can be used to keep track of sets of data. The database itself can be thought of as a kind of electronic filing cabinet and the rest of the system is there to allow users to create and delete files and to get information in and out of the files, In this session you are going to learn how to create a simple "flat file" database and use it to organise a set of data so that it can be queried to answer certain questions.


Required reading

Geekgirls.com databases. Step by step guides to designing and building databases including tutorials and exercises. http://www.geekgirls.com/menu_databases.htm

You are not required to work through them all exhaustively, but you will find that they are short, easy to follow and cover a lot of relevant issues. So take a look at them to decide how many of them you actually need to do and just read the rest for information.


Learning outcomes

By the end of this session you will be able to:

Describe the advantages of using databases to present information on Web sites from the point of view of:

a) the subject expert, and

b) the end user.

Define and give examples of basic database terms such as record, table, field, primary key, index, data type.

Create a single table database to store data that we provide.

Describe and explain the issues associated with creating a single table database eg differences between field types.

Design and build data entry forms and use them to populate your database with the data we provide.

Explain the difference between single and multiple field queries.

Specify and create queries to enable users to interrogate your database usefully.


Activity: Why do we need databases?

Examine the bound copy of "Photographic Exhibitions in Britain 1839-1865" and answer the following questions:

  • How many exhibitors were showing Calotypes between 1845 and 1860?
  • How many photographs did Dr John Adamson exhibit between 1854 and 1864 and how many were from his own negatives?
  • Who showed the most expensive exhibit in this entire set of exhibitions?

Now consult the PEIB Website [1] to answer the same questions. OK, hopefully the point is sufficiently well made with these few examples. Databases can be queried to provide answers to questions that would otherwise take hours/weeks/years/a lifetime to answer if the only way to do it was to sort through the data manually and take notes. What might have been speculation ("I wonder if....") can be turned into focused research if the data are electronically searchable. Better still, if the database is linked to the Web then its contents can be queried by virtually unlimited numbers of users from a huge variety of locations and at times that suit those users.


Activity: What can database driven Web sites do?

Not all Web sites are driven by databases. In the early days of the Web sites were usually just a collection of static pages connected together with hyperlinks and a navigation menu. This kind of site works more or less like an electronic brochure or book. To see what this implies have a look at this Web site: http://bookcoverarchive.com/book/the_error_world.

Look for the number of books by publisher Harper Perennial. Then get a list of publishers and identify the number of books published by them in the website. How easy was this to do?


Next is a database of sheet music, and the link takes you to an example page http://webapp1.dlib.indiana.edu/inharmony/detail.do?action=detail&fullItemID=/lilly/starr/LL-SSM-2-305-0220. How many entries in the database have "Ragtime music" as their local subject? Was this search easier than the previous search? Why?


This site is driven by a database of information which has been structured into different types or "fields". That makes it easy to search for specific types of information across a great number of different items or documents, Instead of searching whole documents and trying to interpret their contents, the search is just looking for pre-defined types of information in the relevant fields.

To learn more about database fields read the introduction to databases in www.geekgirls.com http://www.geekgirls.com/databases_from_scratch_1.htm.


Activity: Field names and information types

Staying with the sheet music example, http://webapp1.dlib.indiana.edu/inharmony/detail.do?action=detail&fullItemID=/lilly/starr/LL-SSM-2-305-0220

List the field names you think they have used and describe their type.


Activity: Building a simple database

Your task in this activity is to build an information resource based on the data held at http://rogerfenton.dmu.ac.uk. Working in pairs, use the data to construct a single table database system in OpenOffice Base that contains all of the information on the website. OpenOffice is a complete, and free, replacement for Microsoft Office including a database application called 'Base'. You can download it from here: http://www.openoffice.org/. You should also download the guide to getting started with Base. 'Base' is the database component of OpenOffice and you can download the pdf guide from here: http://documentation.openoffice.org/manuals/userguide3/0108GS3-GettingStartedWithBase.pdf.

You will need to think about the different types of data it contains, the fields required, and a primary key. You will also need to think about how to get the data into the database and the kinds of questions users might want to put to the database. To help you learn how to do this look at the tutorials dealing with "Databasics" and "Database design from scratch"[2],if you haven't already.

Method:

  • Examine a sample of Fenton's letters.
  • Categorise the different types of contents they contain into "fields" and try to identify the type of information that should go in each field.
  • Using Base, start a new project and create at least 4 records, ie 4 letters.
  • Create a data entry form and use it to add another 2 records.


Activity: Single and multiple field queries

Go back to the Indiana University music site http://webapp1.dlib.indiana.edu/inharmony/detail.do?action=detail&fullItemID=/lilly/starr/LL-SSM-2-305-0220 and use the "search" function to search for the word "Berlin" to see how many hits you get.

Now use the "advanced search" to search for "Berlin" AND "ragtime" ie searching in more than one field.

What happened to the number of hits? Can you explain why? So why are multiple field queries useful?

Now look at the Fenton Website again http://rogerfenton.dmu.ac.uk. What kind of multiple field queries might researchers want to ask of this database? eg. How many letters are from the Annie Grace Fenton letterbook? How many letters did Fenton write to Annie Grace in May?

You will be given a complete set of data in OpenOffice 'Base'. Create search/query forms to enable multiple field queries to be carried out on these data, using the guidance notes in 'Base'.

Seminar preparation

Prepare a brief presentation (maximum 5 wiki pages or Powerpoint slides, not counting references) on what you have done and what you have learned from this session.



Follow this link to the Photography Resources in a Digital Age Contents page to return to the module contents.

Back to the MA: Photographic History Main Page to return to the Course contents.