v.22.7New Feature

Support isNullable Function for Nullable Argument Check

Support isNullable function. This function checks whether it's argument is nullable and return 1 or 0. Closes #38611. #38841 (lokax).
Added support for the isNullable function in ClickHouse, which checks if its argument is nullable and returns 1 if true, or 0 otherwise.

Why it matters

This feature allows users to easily determine whether a column or expression is nullable within their queries, enabling better handling of nullable data types and more dynamic query logic based on nullability.

How to use it

Use the isNullable function in your SQL queries by passing a column or expression as the argument. It returns 1 if the input is nullable, and 0 if it is not. For example:

SELECT isNullable(column_name) FROM table_name;