PostgreSQL provides numerous math functions to perform various mathematical operations, such as ROUND(), SQRT(), etc. All these functions offer different functionality, such as rounding a number to its nearest integer, finding the square root of a number, etc. PostgreSQL offers another useful function named the **FLOOR()** function that rounds down a number to the next whole number.

This blog post will demonstrate the working of the FLOOR() function via practical examples. So, let’s get started.

**How to Use FLOOR() Function in Postgres?**

Postgres **FLOOR()** function is one of the math functions that accept a numeric value or an expression and round down to the next whole number:

FLOOR(num);

- The above snippet shows that the
**FLOOR()**function accepts only a single argument, “num”. - The “num” can be a numeric value or an expression.
- The FLOOR() function retrieves an integer/whole number.
- The return value will always be less than or equal to the given number; the retrieved value cannot exceed the given number.

**Example 1: How Does the FLOOR() Function Work?**

Let’s execute the below command and see how the FLOOR() function works in Postgres:

SELECT FLOOR(72.5772);

In the above snippet, the FLOOR() function takes the number “72.5772”; consequently, it will retrieve the following output:

The output shows that the FLOOR() function rounded down the given number to the nearest integer.

**Example 2: How Does the FLOOR() Function Work With an Expression?**

Let’s pass an expression instead of a number and see how the FLOOR() function works:

SELECT FLOOR(72.5272 + 138.1217);

The output shows that the FLOOR() function calculates the given expression and rounds the number down to the nearest whole number.

**Example 3: How to Use the FLOOR() Function on Table’s Data?**

Firstly, we will create a sample table named “emp_bio” with three columns: emp_id, emp_name, and emp_bio:

CREATE TABLE emp_bio( emp_id INT, emp_name TEXT, emp_sal NUMERIC );

The “emp_bio” is successfully created. Now, we will insert some records/data in the newly created table:

INSERT INTO emp_bio(emp_id, emp_name, emp_sal) VALUES (1, 'Joseph', 50587.7891), (2, 'Mike', 40856.5678), (3, 'Dean', 30756.4321), (4, 'Ambrose', 30712.1234);

Let’s verify the table’s data via the SELECT command:

SELECT * FROM emp_bio;

Now let’s utilize the FLOOR() function on the emp_sal column of the emp_bio table:

SELECT emp_sal, FLOOR(emp_sal) FROM emp_bio;

The output authenticates the working of the FLOOR() function as it successfully rounded down the column’s values to the nearest integers.

**Conclusion**

In PostgreSQL, the **FLOOR()** function is one of the math functions that accept a numeric value or expression and round down the given number to the nearest integer/whole number. The return value will always be less than or equal to the given number; the retrieved value cannot exceed the given number. This blog post presented a detailed guide on the **FLOOR()** function via practical examples.