Perform Calculations | IGCSE Information and Communication Technology Preparation - Year 11 PDF Download

Use of Arithmetic Operations or Numeric Functions

• In a database, arithmetic operations or numeric functions are utilized to perform calculations.
• Calculated Fields in a database are fields that execute a calculation based on other number fields. 
  • For instance, in a products table with Price and Quantity fields, a TotalCost calculated field could be created: TotalCost = Price * Quantity.  This calculation determines the total cost by multiplying the price of each item by its quantity.
• Calculated Fields allow for performing calculations based on numerical data.
  • Calculated Controls are objects positioned on forms or reports to exhibit the result of an expression.
  • For instance, in a sales database form where QuantitySold and UnitPrice are input, a calculated control could display TotalSale: TotalSale = QuantitySold * UnitPrice. This showcases the total sale on the form without storing it in the database.

Using Formulae and Functions to Perform Calculations

• Databases play a crucial role by enabling users to apply formulae and functions for real-time calculations.
• Various basic arithmetic operations like addition, subtraction, multiplication, and division are supported.
• For instance, when dealing with a discount field, a subtraction operation can be executed: FinalCost = TotalCost - Discount.

Aggregate Functions

You can also use aggregate functions to calculate statistical information about a set of records. Some examples include:

• Sum: This function adds up all values within a column. 
  • For example, to determine the total sales cost, you could employ SUM(TotalCost).
• Average: Calculates the mean of a set of numbers in a column. 
  • To find the average product price, use AVERAGE(Price).
• Maximum: Identifies the highest value in a column. 
  • For instance, to pinpoint the costliest item, apply MAX(Price).
• Minimum: Determines the lowest value in a column. 
  • To identify the cheapest product, utilize MIN(Price).
• Count: Tallies the number of rows in a column. 
  • To count the total products in the inventory, run COUNT(ProductID).

Keep in mind that the precise syntax and function names could vary slightly based on the particular database system being utilized.