Building a DatabaseDatabase

What is database ? a collection of data or information that is

organized so that its contents can easily be accessed, managed, and updated.

Type of database Manual database Computerized database

What is the difference between manual

database and computerized

database?

Manual database Lists created on stone, metal or paper

are called manual database. Example: List students’ mark. The list

consists two columns, NAME and MARKS. Teacher fill in the names and marks for each subject according to level : year 7, year 8 etc. These paper files are then stored in filling cabinet.

Manual database – list students’ mark

Manual databaseDisadvantages :

Accesing file and updating is very time consuming. for example when data needs to be retreived or updated, the user has to search through file to locate them physically.

Take up a lot of space since data has to be stored files.

Computerized database Store data and manipulate a database

using computer .

Computerized databaseAdvantages :

Store information only once since most database software allows you to access information from several files.

Validation checks may be made on the data so that there will be fewer errors in the data.

Files can be linked together, which means that if you update one of the files, all the other files that depend on the same information will automatically be updated.

Access information is quickly.

Computerized databaseDisadvantages : If the computer breaks down, you

are not able to access the details. It is easy to copy computer files. Training is needed to use system so that

this takes time and cost money Database may be corrupted / infected. Some database complicated to us.

Parts of databaseDatabases are organized in files which consist of a series of records which in turn consist of a series of fields.

Once your understood this, you will be well on the way to understanding

database.

Parts of database Files - a collection of data or information

that has been given a name.

Parts of database Records – one entry in a database.

Parts of database Fields – records contains a number of

fields. ( each item in a record )

Parts of database : Scenario

1. Information of all student s in a school could be save as student file

2. Student record card - record

3. Student number, forename, form, DOB – field name

Two main types of database flat file database relational database

Two main types of database Flat file database Relational database

Use on personal computer. Used a lot in large organisations.

Store data in one file at a time and this must store all the data.

Store data in separate tables and files.(have links/ relationships which allow data from another file to be shown, used and edited but not copy in a current file. So that whenever the values the other file change, the data displayed in the current file also changes.

Not suitable for large database because they can be slow, have large file size and use a lot of memory.

IMAGE OF RELATIONAL DATABASE

ACTIVITY Activity 1 – brain storming Activity 1 – fill in he blanks Homework