PostgreSQL is a powerful and popular open-source relational database management system. It supports various data types, including the float data type, which allows you to store decimal numbers with a floating-point precision. In this tutorial, we will explore how to use the float data type in PostgreSQL and perform basic operations with it.

## Defining a Float Column

To use the float data type in PostgreSQL, you need to define a column with the float type in your table. Let’s consider an example where we have a table named __products__ with a column named __price__ of type float:

CREATE TABLE products ( id serial PRIMARY KEY, name varchar(255) NOT NULL, price float );

In this example, the __price__ column is defined as **float**. This means that it can store decimal numbers with floating-point precision.

## Inserting Float Values

To insert values into a table with a float column, you need to provide valid float values. For example, let’s insert some sample values into the __products__ table:

INSERT INTO products (name, price) VALUES ('Product 1', 10.99), ('Product 2', 19.99), ('Product 3', 7.50);

In this example, we are inserting three rows into the __products__ table. Each row consists of a name and a price value. The price values are decimal numbers represented as floats.

## Selecting Float Values

To select and retrieve float values from a table in PostgreSQL, you can use simple SELECT statements. For example:

SELECT name, price FROM products;

This query will retrieve the __name__ and __price__ columns from the __products__ table. The __price__ column will be returned as float values.

## Performing Arithmetic Operations with Float Values

In PostgreSQL, you can perform various arithmetic operations on float values. Let’s consider a simple example where we want to calculate the total price of all products:

SELECT SUM(price) AS total_price FROM products;

In this example, we are using the SUM() function to calculate the sum of all prices in the __products__ table. The result is returned as a float value with the alias **total_price**.

## Rounding Float Values

Sometimes, you may need to round float values to a specific decimal precision. PostgreSQL provides several functions for rounding float values, such as ROUND(), CEIL(), and FLOOR(). Let’s see an example using the ROUND() function:

SELECT name, price, ROUND(price, 2) AS rounded_price FROM products;

In this example, we are selecting the __name__, __price__, and a rounded version of the price column using the ROUND() function with a precision of 2 decimal places. The result is returned as a new column called **rounded_price**.

### Note:

- The ROUND() function rounds a float value to the nearest integer or decimal precision specified.
- The CEIL() function rounds up to the nearest integer or decimal precision specified.
- The FLOOR() function rounds down to the nearest integer or decimal precision specified.

## Conclusion

In this tutorial, we explored how to use the float data type in PostgreSQL. We learned how to define a float column, insert and select float values, perform arithmetic operations with floats, and round float values to a specific decimal precision. Understanding and effectively using the float data type in PostgreSQL will allow you to store and manipulate decimal numbers with floating-point precision in your database.