Good job! Up till now, we've written operations with only one condition in the
WHERE clause. However, there are a lot of situations where we'll need to use more than one condition. Here's an example:
UPDATE Exam SET WrittenExamScore = 0
WHERE StudentId = 1
AND Subject = N'Spanish';
It updates the score of the written exam in Spanish for the student with
Id = 1. It checks if the student ID is 1, then checks if the exam subject is Spanish. If both of these are true, then it assigns a zero to the written exam score. The
AND logical operator joins these two conditions.
Of course, you can use more than two conditions. Remember that all conditions joined by an
AND operator have to return
TRUE for the rows to update.
Another operator for multiple conditions is
OR. In this case, it is enough that one of the given conditions is met.