Class O3.S4 (Duration, Element, Other)


=centercr @ []QUERY Q 4.4.1: Find the oldest employee who was a Typist on 12/31/85, and the times when that employee had been a Typist so far.
ANSWER: ``(ED, 4/1/82 – 12/31/85)''
CATEGORY: (Projected, Element, Duration) / (Duration, Element, Explicit) / (=, Constant), (=, Foreign)


=centercr @ []QUERY Q 4.4.2: For employees in the Toy department who had worked less than DI in that department as of 1/1/85, find their names on 1/1/85 and the time difference on 1/1/85.
ANSWER: ``(Ed, 1 month less)''
CATEGORY: (Projected, — ) / (Duration, Element, Explicit) / (=, Constant), (< >, Single)


=centercr @ []QUERY Q 4.4.3: Find the current employees who worked the least during 1987, and the times in 1987 during which they worked.
ANSWER: ``(ED, ((1/1/87 – 1/31/87), (4/1/87 – 12/31/87))''
CATEGORY: (Projected, Element, Intersection) / (Duration, Element, Explicit) / (Nothing)