SELECT least value between two columns with MYSQL

Question

Hello I am trying to select the smallest value between 3 columns with MySQL.

The issue I am facing is that in a column I might have NULL value. How can I get the least value that is not NULL ?

Running select least(1, 3, NULL) will return NULL but I would like to have 1 as an answer.

Thank you for your help.

Answer 1

The way least() handles null s is a documented behavior :

If any argument is NULL , the result is NULL . No comparison is needed.

That might seem annoying, but propagating the null value to the resultset is how your database signals you that one of your values is undefined; this is consistent with the behavior of other operations that involve null (string concatenation, arithmetic operations, ...).

If only the third column may be null , and none of the other two, you could do:

least(col1, col2, coalesce(col3, col1))