Compare values of two columns then select the larger value

Question

I need to query a table and select 3 of the values of 4 columns. I need to compare the values of the 3rd column and the fourth column and select the larger value.

For ex

Answer 1

You can use CASE, but if one of the values is 'null', the 'null' is considered the greatest value.

To solve this problem you can use GREATEST

SELECT GREATEST(column3, column4)
FROM Table1