SQL is a domain-specific language used in programming and design for managing data held in a relational database management system, or for streaming processing in a relational data stream management system.

Some of the functions used in SQL include: 

COUNT – return the number of records returned by a select query

EXP – returns the raised to the power of a specified number

MAX - returns the maximum value in a set of values

MIN - returns the minimum value in a set of values

LEFT – extract a number of characters from a string (starting from left 

AVG – returns the average expression of the process

SUM – used to return the sum of a group of values\

In this pdf I have used the SQL to:

• Display specific columns
• Arrange values in a column in descending order (DESC)
• Calculate totals in a column
• Updating a column I. e Correcting typing mistakes