Topic 8

Information handling software is any software used to store, manipulate and output information. It covers database software, databases created using spreadsheet software and stores of music, sounds and photographs. 

Manipulating data in a data means to perform some sort of operation on a set of data. Data in databases can be manipulated in the following ways: 

• Updating, deleting and searching records
• Search criteria using operators and joining operators

Update- change the data and to bring up-to-date

Delete- remove data no longer needed

Sorting- into an order, i.e. alphabetically or by ascending numerical order

Search- look for specific records that match certain criteria

Operators are used to construct search criteria and include:

= equal

> greater than

< less than

<> not equal

>= greater than or equal to

<= less than or equal to

=Patel (in a surname field finds data for all people with surname Patel) 

=20 (in a quantity field finds data for all occurences where the quantity is 20) 

>01/02/10 (in a date field finds the data for all the dates after, but not including, 01/02/10) 

<>0 (in a quantity field finds the data where the quantity does not equal zero) 

Operators can be joined by AND or OR.

Examples: 

• Size = XL AND Type = Shirt
• Pet = Dog OR Pet = Cat

• Text
• Numbers
• Date
• Time
• Currency
• AutoNumber
• Boolean (when there are only one of two choices that can entered in a field i.e. yes/no or male/female etc) 
• Lists
• Picture
• Sound 
• Video

Data= raw facts and figures about a specific person, place or thing. 

Information= data that has been processed in some way to give it meaning

Field= an item of data about a person or thing i.e. surname, address, etc. 

Record= the detail relating to a single person or thing- a record consists of a number or fields

File= a collection of related records, i.e. all the pupils in a school

Database= an organised store of data on a computer

A field in a database that is used to uniquely identify a record from within a table is a key field or primary key. A key field is a field in an infomration system that is unique to a particular record. 

Search engines, such as Google, and key word searches- to find specific words in a document are the most common ways searches are performed.

Data type check- checks that correct type of data is being entered i.e. text is not put into a number field and vice versa

Range checks are perfomed on numbers to make sure they are between two predetermined figures

Presence check- checks to see that data is always entered into this type of field, something must be entered

Format checks check that data is entered in a specific format, i.e. a postcode must be in the work of 2 letters, 2 numbers then 2 letters, i.e. JE3 1JT

Input masks allow data to be input into a database in a specific format that makes it easier for the person inputting the data, for example, if you wants a telephone number to be entered with the dialling code the input mask to be used could be (00000) 000 000 representing (01534) 111 222

These include: 

• Faster access to data- search engines can be used to quickly access information on the Internet, key word searches can be performed, search criteria can be used to extract specific information from huge databases
• A variety of output formats- on screen, as hard copy (i.e. printed onto paper), as a copy on a disk or another removable media
• Improved data integrity- relates to the correctness of data
• Easy to back up- specify who is responsible for the taking of backups, how often backups are taken, where the backup copies are kept, how data can be recovered from the back ups, state what media is used in the backups and ensure the staff are traine in the recovery of data from back ups
• Security- you can password protect data held in a database