Error in executing factorial part of listing 5-3

[aman-313]

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General

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Windows 10

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Yes

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PostgreSQL = 14
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Issue or Question

Chapter, page and code listing number:
Chapter 5, listing 5-3

Describe the issue or your question:
Code mentioned in book for calculating factorial of a number is not executing successfully. It is showing an error at the end of the syntax. However, for this I am able to use inbulit factorial function. SELECT FACTORIAL(4);

Please paste the code and error message here. It's OK to alter identifying info such as a folder name
SELECT 4 !; -- factorial

ERROR: syntax error at or near ";"
LINE 1: SELECT 4 !; -- factorial
^
SQL state: 42601
Character: 11

[anthonydb]

Thanks for noting this, @aman-313!

Beginning with PostgreSQL 14, released in September 2021, the factorial operator (!) has been deprecated. Instead, we must use the factorial() function.

I have made a note in the FAQ and updated Listing 5-3 with a note and the function.

The factorial operator has been removed in the upcoming 2nd Edition of the book as well.