Amazon Redshift will no longer support the creation of new Python UDFs starting November 1, 2025. If you would like to use Python UDFs, create the UDFs prior to that date. Existing Python UDFs will continue to function as normal. For more information, see the blog post .

ASCII function

The ASCII function returns the ASCII code, or the Unicode code-point, of the first character in the string that you specify. The function returns 0 if the string is empty. It returns NULL if the string is null.

Syntax

ASCII('string')

Argument

Return type

INTEGER

Examples

To return NULL, use the following example. The NULLIF function returns NULL if the two arguments are the same, so the input argument for the ASCII function is NULL. For more information, see NULLIF function.

SELECT ASCII(NULLIF('',''));

+-------+
| ascii |
+-------+
|  NULL |
+-------+

To return the ASCII code 0, use the following example.

SELECT ASCII('');

+-------+
| ascii |
+-------+
|     0 |
+-------+

To return the ASCII code 97 for the first letter of the word amazon, use the following example.

SELECT ASCII('amazon');

+-------+
| ascii |
+-------+
|    97 |
+-------+

To return the ASCII code 65 for the first letter of the word Amazon, use the following example.

SELECT ASCII('Amazon');

+-------+
| ascii |
+-------+
|    65 |
+-------+