v.20.4New Feature

add joinGetOrNull to return NULL for missing keys

Official CH changelog text
add joinGetOrNull to return NULL when key is missing instead of returning the default value. #10094 (Amos Bird)
joinGetOrNull function added to return NULL when the key is missing instead of a default value.

Why it matters

This feature addresses the need to distinguish missing keys in join operations by returning NULL rather than a generic default value, providing clearer and more accurate query results when the key does not exist.

How to use it

Use the new joinGetOrNull function in your queries to retrieve values from a joined table. If the specified key is not found, it will return NULL instead of the default value. Example usage:

SELECT joinGetOrNull('table_name', 'column_name', key) FROM your_table;

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