v.24.7Improvement

Allow concat function with empty arguments in ClickHouse

Official CH changelog text
Allow to use concat function with empty arguments :) select concat();. #65887 (李扬).
Allows the concat function to be called with no arguments, returning an empty string.

Why it matters

Previously, calling concat without any arguments was not allowed or caused an error. This feature enables more flexible query writing by permitting concat to handle empty argument lists gracefully, simplifying dynamic SQL generation and avoiding additional checks for argument presence.

How to use it

Simply call concat without any arguments in your query, like this:

SELECT concat();

This will return an empty string instead of producing an error.

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