PostgreSQL Function - A Complete Guide

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Check out this article on PostgreSQL Function.
Learn What It Is, How It Works and how you can create a function in PostgreSQL

:zap: Here’s a sneak peek at how PostgreSQL functions work (taken from the article)

How do PostgreSQL Functions work?

Each PostgreSQL function has an exact purpose different from all other functions in the database. However, all of them follow a basic workflow defined by three steps.

Step-1 : Creating a function

  • The first step is to use the CREATE function statement to define a new function or use the REPLACE function statement to redefine an existing function.

  • The syntax of the CREATE function statement includes a unique name, input parameters, return type, and logic of the function.

  • A set of SQL statements are included in the function body, which acts as the logical definition of the function. These statements define the function’s operation when it is called in a PostgreSQL code.

  • The syntax also has a language parameter to define the language in which the function is written( supports many languages, such as SQL, C, Python, etc).

Step-2 : Calling the function

  • To use the newly created function in other codes, call it and execute the SQL statements written in its logic part.

  • First, the input values or parameters are captured in the given code to define what the function operates on.

  • PostgreSQL codes for enterprises can have loops and structures to perform similar tasks in multiple ways.
    For eg: The LOOP control function can be used to repeat the same task until a specific condition is met.

  • Once the code is executed, it moves to the next part: the return value.

Step-3 : Return

  • The "result” given back by the code to the database is called the return value.

  • The form of the return value is specified in the syntax by: RETURN return_type

  • The return type can be scalars, integers, other simple values, or even complex data structures.

  • The return value can be displayed as the result of the code using the PRINT statement or assigned to a variable for use in another code.

To learn more about this in detail, read the full article here⤵️

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