Database Anatomy

9ISTT3L2 Databases

Databases

• Hold raw ‘data’ that is used as building blocks to build information we want

• Large databases and small databases all use the same theory of operation.

• Some databases are huge (Google)

• Some databases ‘talk’ to other databases

• We put data in, and get information out most of the time.

Where are they hiding?

Accessing a database

• How fast is my DSL?

• Well to find out I need to test it.

• To do that I need to use a database to find a website that does it (Google)

• And that website will have a database of where I can go to do the test.

• Here is a test

Structures of a database

• A database stores ‘data’ in a TABLE.

• A table consists of ROWS and COLUMNS

• All the data in the table is entered, stored and retrieved in a CELL

• A CELL is one single piece of data in a table

• A cell is referenced by its postion in a ROW and a COLUMN

A table of rows and columns

A simple TABLE

A MS Excel Worksheet is in fact a TABLE of data.

It can be used in a DATABASE easily.

It has ROWS, COLUMNS and CELLS

We can put information into a CELL

Each Cell has a reference

A1 or C13

EXCELL is…

• It is called a FLAT FILE DATABASE• It has the characteristics of a Database• ROWS, COLUMNS, CELLS• It only has one TABLE• So all the data has to be entered into a

single TABLE.• Each ROW is a RECORD• Each COLUMN is a FIELD.

FIELDS

A FIELD is the name given to a piece of data in a cell.

DATABASES use fields to allow data to be added/deleted and modified.

DATABASES search for data using these FIELDS

Over on the left, identify the THREE fields that are being used to record data.

RECORDS

A record is a complete ‘piece’ of information in a DATABASE.

For example …

Here we have 3 fields

…what are they?

Data is entered in a row that corresponds to a field.

How many RECORDS are in this database TABLE?

Summary

• Key terms to define (know) at this stage.• DATABASE• DATA verses INFORMATION• TABLE• ROW, COLUMN• CELL• FIELD• RECORD

Activity 2

• Using your survey• Identify the FIELDS that you asked people to fill

in• Create these FIELDS in Excel (using

COLUMNS)• Highlight the fields using BOLD RED• Enter the responses you have as RECORDS.• There is NO need to enter the questions

again in EXCEL – they do need to be put on your WORDPRESS site.

Homework

• Open a selling item on eBay (or use this one as an example)

• Identify the FIELDS of data that are being displayed.

• Identify the TYPE of data in each of these fields.

• Print/Screenshot an annotated diagram to illustrate your identification

Extension and further reading

• Click here for database information res