MariaDB is an open-source relational database management system that stores organize and manipulate data very efficiently. It is considered a replacement for MySQL. It offers various features like multi-master replication, enhanced storage engines, and so on.

In this article, we will learn about the MariaDB function with the CREATE, VERIFY, and DROP functions. A database function is a program that takes arguments and executes a task such as complicated operations. It is used to return an output value. we will learn the syntax, create functions, and drop functions with detailed information. the create function helps database management to operate the many functionalities according to the operation.

MariaDB Function

A MariaDB function is a type of stored program to accepts the parameters and gives an output value. MariaDB gives users the ability to write custom functions using the create function operation. Additionally, it makes it easier to remove or eliminate an existing MariaDB database function. we can verify the function with the SELECT query with the function name and its input parameter.

The MariaDB function helps to manage the database information and its complicated operations. MariaDB Database functions are used to allow the ability to increase the database server’s capabilities.

In MariaDB, functions can be operated on two functionality.

• CREATE Function

• DROP Function

Create Function

The Create function is used to create new functions to handle complicated data and return values. We can customize our function in the mariaDB database. The create function makes it easy to add any operational, logical, and mathematical code for the database information and get the output according to the operation.

Syntax:

The following syntax is used to create a new function in the mariaDB database. The syntax shows the complicated but Return output_datatype is required with or without optional values. We can declare and execute the code of the database information.

CREATE   
[ DEFINER = { CURRENT_USER | user_name } ]   
FUNCTION function_names [ (parameter_name datatype [, parameter_name datatype]) ]  
RETURNS output_datatype [ LANGUAGE SQL  
| DETERMINISTIC  
| NOT DETERMINISTIC  
| { CONTAINS SQL   
| NO SQL  
| READS SQL DATA  
| MODIFIES SQL DATA }  
| SQL SECURITY { DEFINER | INVOKER }  
| COMMENT 'comment_value'  
BEGIN  
   declaration_section  
   executable_section  
END;   

Explanation:

• DEFINER clause: The DEFINER clause is a optional clause. The user is created the function with the own definer. We have to contain the DEFINER clause with required user_name. We can specify a different definer apart from the user.
• function_name: This parameter is provided function name in the MariaDB.
• return_datatype: This defines the type of data that the function provides the output data.
• LANGUAGE SQL: It is included in the syntax for portability, but its functionality is unaffected.
• DETERMINISTIC: This indicates a set of input parameters and the function gets a single output.
• NOT DETERMINISTIC: It is depending on the input parameters and the function provides a different outcome. The Random numbers, server factors, or table data have an impact on the outcome.
• CONTAINS SQL: MariaDB database is informed by this instructive clause that the function contains SQL. The database does not confirm this clause for the function.
• NO SQL: this is a optional informative clause that doesn’t affect the function. it is not used in the database.
• READS SQL DATA: A statement is informing MariaDB that does not alter any data. It is used the “SELECT” statements to read data.
• MODIFIES SQL DATA: A MariaDB function is used DDL commands such as INSERT, UPDATE, DELETE, or others SQL data.
• declaration_section: the part of the function is used to declare local variables.
• executable_section: The part of the function is used to operate code.

Example of Create Function

The example shows create new function in mariaDB database using basic requirements. we can create parameter to input the data for the function. We can set value and add the addition functionality with the parameters. The output value returns the addition of the while statement’s condition with the input value.

Query:

DELIMITER //  
CREATE FUNCTION MainValue ( initial_value INT )  
RETURNS INT DETERMINISTIC  
BEGIN  
   DECLARE final_value INT;  
   SET final_value = 0;  
   labels: WHILE final_value <= 2000 DO  
     SET final_value = final_value + initial_value;  
   END WHILE labels;  
   RETURN final_value;  
END; //  
DELIMITER ;

Verification

We can verify the function of the mariaDB database. The “MainValue” function add the “20” value to get the addition of the parameter. We can get output of the given function with the input parameters.

Query:

SELECT MainValue(20);

Output:

Create MariaDB Function

Explanation:

• The “initial_value” is the input parameter of the mariadb function.
• The deterministic is used to get the single output.
• we can set the final value as a zero to operate with the function.
• The “while” condition set the “2000” greater than equal to final_value parameter.
• The function is used for addition operation with the loop.
• The verification function set with the 20 input value.
• The function returns the 2000+20 as a functionality and get the 2020 output.
• Create function is required the query with the input parameter.
• Verify function is required input value to operate the mariaDB function.

Drop Function

The DROP Function is used to delete available and unwanted functions in the mariaDB. If the user knows the name of function which is available then it may easily drop the function directly. If the user confuse with the function name then use the “IF EXISTS” option is used in the database query.

Syntax:

DROP FUNCTION [ IF EXISTS ] function_names;  
OR
DROP FUNCTION function_names;  

Explanation of Syntax:

• The “function_names” is available function name which is required to delete from database.
• The [ IF EXISTS ] is the optional keyword which is used if user is unaware about function name.

Example of DROP Function

The example shows delete old function in mariaDB database using basic requirements. the drop function can remove function from database permanently.

DROP function MainValue;

Output:

Drop MariaDB Function

Explanation: In the above Query, We have seen the DROP Function query is used to delete the “MainValue” function.

Conclusion

In the mariaDB database function, we can CREATE, SELECT and DROP function for the complicated information and its operation. It helps to handle and operate the different data types of the value with the database statement. The database function is used to operate and modify the basic code to get the required output of the input value. It helps in code reuseability and save time and effort during writing the same code in each query.