Databases

Databases: 

Databases What are they?

What is a database?: 

What is a database? telephone directory address book doctor/dentist patient records cinema bookings Internet! School data sheets on you!

OK…don’t laugh…but..: 

OK…don’t laugh…but.. One example of a database is a MP3 player. Ipods store files in the following system: Can you do any better? Add your own choice of records to Task 1.

Sorted!: 

Sorted! One great feature of databases is that it can SORT data into ORDER…. Through many fields…. Do you have the skills to do this yourself? Put the following data into Ascending order… OK… so what are the 1st 5 names? Adam Ahmad Amy Charlie Christopher Danielle Dom Edward James Lizzie Matthew Michaela Nathalie Robert Ross Samantha Stanley Thomas Vincent So now go to your worksheet and complete task 2!

Task 2 answers…: 

Task 2 answers… Q1: If this database was put into ascending order by name – who would be 1st and last in the list? Bongo & Tarsa Q2: If this database was put into descending order by Type order – who would be 1st and last in the list? Zebra & Crocs Q3: If this database was put into into descending order by age order – who would be 1st and last in the list? Gorilla & Snake So get the hint…. A database can SORT a lot of data QUICKLY into any order that you want… ascending or descending by any data fields

Data Types: 

Data Types Alphabetic – only letters are allowed. Example fields: First name Colours Animal type Numeric – only numbers are allowed: Example fields: Age Height Speed/m.p.h. Percentage

Data Types: 

Data Types Alpha_numeric – this uses letters and numbers together. Examples: Tutor Groups Postcode NI number Currency – uses currency signs! Pound, dollar, Euro etc. Time – hours, minutes, seconds Date – day, month, year

Data Types: 

Data Types Boolean – exam board favourite! This data type has only 2 choices for the PC user to select… Examples: Yes / No Male / Female On / Off Memo – contains lots of words Container – image, sound, video Auto-number – this automatically generates a number every time a new record is created

Now to your worksheet: 

Now to your worksheet Label your copy of this database file with the correct Data types. alphabetic Memo alphanumeric date numeric Boolean!

Types of Databases: 

Types of Databases Flat File - A flat file database deals with one data file at a time. Each record contains the same field headings. The data held can be 'interrogated' by carrying out searches and sorts and producing reports. Relational - Related items of data can be stored in separate files so that the data is accessed only when needed. This cuts down on the number of separate data items stored in the computer memory. Distributed - It is a large-scale relational database with on-line features for users to contact the system. A user has direct access to the database from his or her computer terminal. The database contacted could be miles away (even in a different country). The connection is through a WAN network through a modem. Access to a distributed database is strictly controlled, with users being allowed into specific parts of the system at a time. Security of the data is very carefully monitored. OR in other words… The school database with Y11 student timetable in it… The school class-room database that gives each room, teacher, Year group & subject for every room, every lesson, for each day!

… Types of databases.: 

… Types of databases. Flat File – your MP3 file, your mobile phone file of phone numbers – only stores the USERS data under one file name.

Relational Database: 

Relational Database Data is stored in separate files Examples include Police files database School database Travel Agents DVLA (car registration) linked to Insurance linked to police queries But who do these agencies link their database files to??? Travel Agent Airplane company Car Hire Company Hotel

Distributed Databases: 

Distributed Databases This is a large-scale relational database with on-line features for users to contact the system. Cinema bookings On-line supermarkets Travel Agents Secret service

Computerised databases…: 

Computerised databases… Can hold a vast amount of data Very fast to find a specific record Can easily search for a specific criteria e.g. "all of the people who live in Warwick“ Can perform analysis on the data e.g. ‘most popular selling item’ Data can be sorted into ascending or descending order on any criteria Can easily update or amend a record e.g customer moves house Records are stored safely and are not easily lost Easy to make a back-up in case of data loss

Paper-based databases: 

Paper-based databases Limited by physical storage space available Can take a while to manually search through all of the records Difficult to search for a specific criteria, every record would have to be manually looked at. Very difficult to analyse the data. Can only store data ascending or descending under one criteria e.g. surname Changes have to be done manually, records can look messy if scribbled out. Records can be lost or misfiled, making it hard to find them. Difficult to make a back up in case of data loss

Which are manual & which are computerised database issues?: 

Which are manual & which are computerised database issues? Complete the questions on your work sheet