CREATE TABLE scientists (SSN VARCHAR, name VARCHAR); CREATE TABLE projects (hours INTEGER, code VARCHAR); CREATE TABLE assignedto (project VARCHAR, scientist VARCHAR)
Find the total hours of the projects that scientists named Michael Rogers or Carol Smith are assigned to.
SELECT SUM(T2.hours) FROM assignedto AS T1 JOIN projects AS T2 ON T1.project = T2.code JOIN scientists AS T3 ON T1.scientist = T3.SSN WHERE T3.name = 'Michael Rogers' OR T3.name = 'Carol Smith'