How to set a value to true or false by null check in TSQL?

Question

What is the right syntax to return TRUE if the field is not NULL and to return FALSE if it is NULL in TSQL?

SELECT -- here return TRUE if table.Code IS NOT NULL. And FALSE otherwise
FROM table

Vermillion

Answer 1

 select case 
           when code IS NULL then 'false'
           else 'true'
        end as result
 from the_table

Unbind

"return TRUE if table.Code IS NOT NULL" – Booth

Answer 2

There is no true or false in mssql. You can use the datatype bit and consider 1 as true and 0 as false:

SELECT CASE WHEN Code IS NULL THEN CAST(0 AS BIT) ELSE CAST(1 AS BIT) END as Result
FROM table 

Beeswing

Answer 3

For fun:

SELECT 
   ISNULL(NULLIF(ISNULL(code,0),code),1) 
FROM table

Booth

I agree for fun, poor maintenance team. – Proceed

Answer 4

int's are cast into true, so:

CAST(ISNULL(int, 0) AS bit)

You can use Length(x) if its a string type

Secrete