PostgreSQL EXP() Function

Summary: in this tutorial, you will learn how to use the PostgreSQL EXP() function to calculate the exponential of a number.

Introduction to the PostgreSQL EXP() function

An exponential of a number is the number e, approximately equal to 2.71, raised to a given power (eⁿ).

In PostgreSQL, you can use the EXP() function to calculate the exponential of a number.

Here’s the syntax of the EXP() function:

EXP(n)Code language: SQL (Structured Query Language) (sql)

In this syntax:

n is the number that you want to calculate the exponential. It can be a literal number, an expression, or a table column.

The EXP() function returns the exponential of a number in double precision. The EXP() function returns NULL if the n is NULL.

If n is a string, the EXP() function will attempt to convert it to a number before calculating the exponential. If the conversion fails, the EXP() function will raise an error.

PostgreSQL EXP() function examples

Let’s take some examples to practice the EXP() function.

1) Basic EXP() function examples

The following example uses the EXP() function to return the exponential of 1:

SELECT EXP(1) result;Code language: SQL (Structured Query Language) (sql)

Output:

      result
-------------------
 2.718281828459045
(1 row)Code language: SQL (Structured Query Language) (sql)

It returns the Euler number (e) because e¹ is e.

The following statement uses the EXP() function to return the exponential of zero:

SELECT EXP(0) result;Code language: SQL (Structured Query Language) (sql)

Output:

 result
--------
      1
(1 row)Code language: SQL (Structured Query Language) (sql)

It returns 1 because e⁰ is 1.

2) Using the EXP() function with numeric strings

The following example uses the EXP() function with a numeric string:

SELECT EXP('10') result;Code language: SQL (Structured Query Language) (sql)

Output:

        exp
--------------------
 22026.465794806718
(1 row)Code language: plaintext (plaintext)

In this example, the EXP() function converts the string ’10’ to the number 10 before calculating the exponential of 10.

The following example raises an error because the function fails to convert the string ’10x’ to a number:

SELECT EXP('10X') result;Code language: SQL (Structured Query Language) (sql)

Error:

ERROR:  invalid input syntax for type double precision: "10X"
LINE 1: SELECT EXP('10X') result;
                   ^Code language: plaintext (plaintext)

Summary

Use the EXP() function to calculate the exponential of a number.

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