Perform Calculations (Cambridge (CIE) IGCSE ICT)

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In a database, you can use arithmetic operations or numeric functions to perform calculations
Calculated fields are fields that carry out a calculation based on other number fields in the database
- For example, a 'products' table with a stock and unit_price fields
- You could use a calculated field named stockvalue to calculate unit_price * stock
- This calculation multiplies the price of each item by its quantity to find the total value of the stock

Adding a calculated field to a database table

Calculated controls are objects you place on forms or reports to display the result of an expression
- For example, a form in a sales database where you input the QuantitySold and UnitPrice
- A calculated control could be used to display the TotalSale
- TotalSale = QuantitySold * UnitPrice
- This displays the total sale on the form without storing it in the database

Databases allow you to use formulae and functions to perform calculations at run time
This can include basic arithmetic operations: addition, subtraction, multiplication, and division
For example, you have a discount field and you want to subtract it from the total cost, you could use a subtraction operation like this:
- FinalCost = TotalCost - Discount

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

Sum	Adds together all the numbers in a column	`SUM(TotalCost)`
Average	Computes the average of a set of numbers in a column	`AVERAGE(Price)`
Maximum	Finds the highest number in a column	`MAX(Price)`
Minimum	Finds the lowest number in a column	`MIN(Price)`
Count	Counts the number of rows in a column	`COUNT(ProductID)`

Remember that the actual syntax and function names might differ slightly depending on the specific database system being used.

the (exam) results speak for themselves:

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