human
Schema:
Scientists (SSN, Name)
Projects (Code, Name, Hours)
AssignedTo (Scientist, Project)
Please answer with SQL.
assistant
Sure, I understand.
human
how many projects are there?
assistant
SELECT COUNT( * ) FROM Projects;
human
among them, how many are not assigned yet?
assistant
SELECT COUNT( * ) FROM Projects WHERE Code NOT IN ( SELECT Project FROM AssignedTo ) ;