How do you create a function?
A function in SQL is created with the CREATE FUNCTION command.
General form:
sql
CREATE FUNCTION function_name(parameters)
RETURNS data_type
AS
BEGIN
-- function body
RETURN value;
END;Example
sql
CREATE FUNCTION get_full_name(first_name VARCHAR(50), last_name VARCHAR(50))
RETURNS VARCHAR(100)
AS
BEGIN
RETURN CONCAT(first_name, ' ', last_name);
END;Now you can use it in queries:
sql
SELECT get_full_name('Ivan', 'Petrov');Note: the syntax can vary slightly between DBMSes (e.g. PostgreSQL, MySQL, SQL Server), but the logic is the same everywhere - a function takes arguments, runs a computation, and returns a result.
Short Answer
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