PostgreSQL LOWER function (original) (raw)

Last Updated : 15 Jul, 2025

In **PostgreSQL, the **LOWER() function is a powerful tool used to convert strings, expressions, or values in a column to lowercase. This function is essential for text normalization, making data comparisons easier and more consistent.

Let's look into the syntax, and usage of the LOWER() function in **PostgreSQLwith detailed examples.

What is the LOWER() Function in PostgreSQL?

The **LOWER() function takes an input string and converts all the characters to lowercase. This is particularly useful when you need to perform case-insensitive comparisons or store data in a uniform format.

**Syntax

**LOWER(string or value or expression)

Parameter

**string_or_value_or_expression: This argument can be a string, a value, or an expression that you want to convert to lowercase.

PostgreSQL LOWER function Examples

Let us take a look at some of the examples of **LOWER Function in **PostgreSQL to better understand the concept.

**Example 1: Converting Column Values to Lowercase

The below statement uses LOWER function to get the full names of the films from the '**Film' table of the sample database, ie, dvdrental:

**SELECT LOWER(title) from film;

**Output:

PostgreSQL LOWER function Example

**Explanation: Here, the LOWER() function converts the title column values to lowercase.

**Example 2: Converting a String to Lowercase

The below statement converts an upper case string to lower case:

**SELECT LOWER('GEEKSFORGEEKS');

**Output:

PostgreSQL LOWER function Example

**Explanation: The **LOWER() function converts the input string '**GEEKSFORGEEKS' to '**geeksforgeeks'.

Important Points About the PostgreSQL LOWER() Function

The LOWER() function consistently converts all characters in the input to lowercase.

The function is useful for making case-insensitive comparisons.

Use the **CAST function to convert non-string values to strings if necessary.

Applicable to strings, expressions, and column values.