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sqloracle-databaseoracle9i

Greatest not null column

I need to update a row with a formula based on the largest value of two DATETIME columns. I would normally do this:

GREATEST(date_one, date_two)

However, both columns are allowed to be NULL. I need the greatest date even when the other is NULL (of course, I expect NULL when both are NULL) and GREATEST() returns NULL when one of the columns is NULL.

This seems to work:

GREATEST(COALESCE(date_one, date_two), COALESCE(date_two, date_one))

But I wonder... am I missing a more straightforward method?

Solution

  • COALESCE(GREATEST(date_one, date_two), date_one, date_two)