bit in SQL Server: 0, 1 and NULL

bit is SQL Server’s yes/no. It stores 0, 1, or NULL. SSMS often shows it as a checkbox. Reports still want a word.

Label it for a human

SELECT product_name,
       CASE WHEN is_discontinued = 1 THEN 'Yes'
            WHEN is_discontinued = 0 THEN 'No'
            ELSE 'Unknown' END AS discontinued
FROM Products;

WHERE is_discontinued = 0 does not include NULL. If the flag was never set, those rows vanish. Say whether unknown counts as no.