Pure Transact SQL (n'utilisant pas d'appel SQL dynamique qui ne fait pas partie de TSQL) :
SELECT
CASE WHEN c1 IS NULL THEN 0 ELSE 1 END
+ CASE WHEN c2 IS NULL THEN 0 ELSE 1 END
+ CASE WHEN c3 IS NULL THEN 0 ELSE 1 END
+ CASE WHEN c4 IS NULL THEN 0 ELSE 1 END
+ CASE WHEN c5 IS NULL THEN 0 ELSE 1 END
+ CASE WHEN c6 IS NULL THEN 0 ELSE 1 END
+ CASE WHEN c7 IS NULL THEN 0 ELSE 1 END
+ CASE WHEN c8 IS NULL THEN 0 ELSE 1 END
FROM T