4.1 In the tblEmployees table the ID field is intended to save the identity number of the employee, for example 012205701708 - NSC Information Technology - Question 4 - 2017 - Paper 2

None of the other fields can serve as primary keys because they may contain duplicate values. For instance, fields such as DateStarted or DateCompleted can have the same dates for multiple job cards, thus failing to meet the requirement of having unique values.

The NumDaysTaken field can be calculated using the DateStarted and DateCompleted fields, making it redundant. Therefore, removing it will simplify the database structure without losing important information.

EmployeeID

tblJobCards

Verifying information entails ensuring that the data corresponds to the original source material and confirms correctness. This can be done through cross-checking, validation routines, and user confirmation at the point of data entry.

The programmer can implement a validation function that checks the value of the gender input against predefined valid options (M or F). A common approach is to use an if-statement that verifies the input value before it is accepted into the program. For example:

if gender_input in ['M', 'F']:
    proceed_with_processing(gender_input)
else:
    prompt_for_valid_input()

SELECT OrderNum, Description, OrderDate
FROM tblEquipment
WHERE Delivered = false
AND Year(OrderDate) = 2016;

UPDATE tblEquipment
SET Delivered = true
WHERE Description = 'Broom';

SELECT Teacher, COUNT(*) AS numOrders
FROM tblClassroom
INNER JOIN tblEquipment ON tblClassroom.RoomNumber = tblEquipment.RoomNumber
GROUP BY Teacher;