What is a function?
A function is a predefined formula which takes one or more arguments as input then process the arguments and returns an output.
There are two types of SQL functions, aggregate functions, and scalar(non-aggregate) functions. Aggregate functions operate on many records and produce a summary, works with GROUP BY whereas non-aggregate functions operate on each record independently.
There are so many built-in functions in SQL to do various calculations on data.
Types of SQL functions
|SQL Aggregate Function||This function can produce a single value for an entire group or table.
They operate on sets of rows and return results based on groups of rows.
Some Aggregate functions are -
|SQL Arithmetic Function||A mathematical function executes a mathematical operation usually based on input values that are provided as arguments, and return a numeric value as the result of the operation. Mathematical functions operate on numeric data such as decimal, integer, float, real, smallint, and tinyint.
Some Arithmetic functions are -
|SQL Character Function||A character or string function is a function which takes one or more characters or numbers as parameters and returns a character value. Basic string functions offer a number of capabilities and return a string value as a result set.
Some Character functions are -
Practice SQL Exercises
- SQL Exercises, Practice, Solution
- SQL Retrieve data from tables [33 Exercises]
- SQL Boolean and Relational operators [12 Exercises]
- SQL Wildcard and Special operators [22 Exercises]
- SQL Aggregate Functions [25 Exercises]
- SQL Formatting query output [10 Exercises]
- SQL Quering on Multiple Tables [8 Exercises]
- FILTERING and SORTING on HR Database [38 Exercises]
- SQL JOINS
- SQL SUBQUERIES
- SQL Union[9 Exercises]
- SQL View[16 Exercises]
- SQL User Account Management [16 Exercise]
- Movie Database
- BASIC queries on movie Database [10 Exercises]
- SUBQUERIES on movie Database [16 Exercises]
- JOINS on movie Database [24 Exercises]
- Soccer Database
- BASIC queries on soccer Database [29 Exercises]
- SUBQUERIES on soccer Database [33 Exercises]
- Hospital Database
- Employee Database
- More to come!
Want to improve the above article? Contribute your Notes/Comments/Examples through Disqus.
SQL: Tips of the Day
How to declare a variable in MySQL?
You can initialize a variable using SET or SELECT statement:
SET @start = 1, @finish = 10;
SELECT @start := 1, @finish := 10; SELECT * FROM places WHERE place BETWEEN @start AND @finish;
- New Content published on w3resource:
- HTML-CSS Practical: Exercises, Practice, Solution
- Java Regular Expression: Exercises, Practice, Solution
- Scala Programming Exercises, Practice, Solution
- Python Itertools exercises
- Python Numpy exercises
- Python GeoPy Package exercises
- Python Pandas exercises
- Python nltk exercises
- Python BeautifulSoup exercises
- Form Template
- Composer - PHP Package Manager
- PHPUnit - PHP Testing
- Laravel - PHP Framework