How to check a column contains null value using SQL's in Spanner Database

Question

How to check a column containing null value using SQL's in Spanner Database. I have both String and Timestamp columns types. When I try to write the below query I am always getting value in the column as result .If the column is null its prints like null;

        select 
         case when t.locked_by IS  null   then 'A'
            else t.locked_by
          end
    from Temp1 t where name='test2'

Answer 1

I can't really see anything wrong with the query, and I cannot reproduce the issue myself. But you could try to use COALESCE instead of the CASE WHEN operator:

SELECT COALESCE(t.locked_by, 'A')
FROM Temp1 t
WHERE name='test2'