SQL Functions

SQL has a lot of built-in functions can be used for counting and calculations.

SQL Aggregate Functions

SQL Aggregate functions calculate the value obtained from the column to return a single value.

Useful Aggregate Functions:

• AVG () - Returns the average
• COUNT () - Returns the number of rows
• Returns the value of the first record - FIRST ()
• LAST () - Returns the value of the last record
• MAX () - Returns the maximum value
• MIN () - Returns the minimum value
• SUM () - Returns the total

SQL Scalar Functions

SQL Scalar functions based on the input value and return a single value.

Useful Scalar Functions:

• UCASE () - a field will be converted to uppercase
• LCASE () - a field will be converted to lowercase
• MID () - extract characters from a text field
• LEN () - Returns the length of a text field
• ROUND () - for a specified number of decimal places a numeric field rounding
• NOW () - Returns the current system date and time
• Display format of a field - FORMAT ()

Note: In the following sections, we will explain in detail the function Aggregate and Scalar Functions.