Comment by chrstr

  CREATE TABLE data_a AS (SELECT 'a' AS test_case, 1 AS value);
  CREATE TABLE data_b AS (SELECT 'b' AS test_case, 2 AS value);
  CREATE VIEW data AS (SELECT * FROM data_a UNION ALL SELECT * FROM data_b);

  CREATE VIEW complicated_query AS (SELECT test_case, value+1 FROM data);

  SELECT * FROM complicated_query WHERE test_case = 'a';
  SELECT * FROM complicated_query WHERE test_case = 'b';