What is the best way to convert an int or null to boolean value in an SQL query?

SELECT
    CASE WHEN ValueColumn IS NULL THEN 'FALSE' ELSE 'TRUE' END BooleanOutput
FROM
    table

select (column_name is not null) as result from table_name;

SELECT
    CASE
        WHEN thevalue IS NULL THEN 0
        ELSE 1
    END AS newVal
FROM .... (rest of select)

create function dbo.isNotNull(@a int)
returns bit
as
begin
return isnull(@a-@a+1,0)
end

select dbo.isNotNull(myIntColumn) from myTable

isnull(column - column + 1, 0) != 0

SELECT DECODE( col, NULL, 0, 1) FROM ...