PostgreSQL INITCAP() Function

Summary: in this tutorial, you will learn how to use the PostgreSQL INITCAP() function to convert a string to a proper case.

Introduction to PostgreSQL INITCAP() function

The INITCAP() function converts the first letter of each word in a string to uppercase and the rest to lowercase. In other words, the INITCAP() function converts a string to a proper case.

Technically, words are defined as sequences of alphanumeric characters separated by non-alphanumeric characters.

Here’s the basic syntax of the INITCAP() function:

INITCAP(text)

In this syntax, the text is a string you want to convert to a proper case. Its type can be CHAR, VARCHAR, or TEXT.

The INITCAP() returns the text in a proper case. It returns NULL if the text is NULL.

To convert a string to lowercase, you use the LOWER() function. To convert a string to uppercase, you use the UPPER() function.

PostgreSQL INITCAP() function examples

Let’s explore some examples of using the INITCAP() function.

1) Basic PostgreSQL INITCAP() example

The following example uses the INITCAP() to convert the string ‘hello john’ to the proper case:

SELECT INITCAP('hello john');

Output:

initcap
------------
 Hello John
(1 row)

2) Using PostgreSQL INITCAP() with table data example

In practice, you often use the INITCAP() function to format blog titles, author names, and so on. For example:

First, create a new table called blog_posts and insert some rows into it:

CREATE TABLE blog_posts(
    id SERIAL PRIMARY KEY,
    title VARCHAR(255) NOT NULL
);

INSERT INTO blog_posts(title)
VALUES
    ('getting started with postgresql'),
    ('advanced postgresql queries'),
    ('postgresql performance optimization'),
    ('postgresql data modeling techniques'),
    ('using postgresql in web development')
RETURNING *;

Output:

id |                title
----+-------------------------------------
  1 | getting started with postgresql
  2 | advanced postgresql queries
  3 | postgresql performance optimization
  4 | postgresql data modeling techniques
  5 | using postgresql in web development
(5 rows)

Second, use the INITCAP() function to update the titles in the blog_posts table to the proper case:

UPDATE blog_posts
SET title = INITCAP(title)
RETURNING *;

Output:

id |                title
----+-------------------------------------
  1 | Getting Started With Postgresql
  2 | Advanced Postgresql Queries
  3 | Postgresql Performance Optimization
  4 | Postgresql Data Modeling Techniques
  5 | Using Postgresql In Web Development
(5 rows)


UPDATE 5

Summary

Use the PostgreSQL INITCAP() function to convert a text to the proper case.