Comment to Exam Question 3a_澳门葡京手机版app下载

egork
2021-06-16T08:34:20.503Z
type:structured-message
www.uio.no

Request:

One of the subqueries has

SELECT T1.A
FROM T1, T2
WHERE T1.A = T2.B AND T2.C > T.X

how can we compare T2.C > T.X? when we have only T1 and T2 in the FROM clause?

Answer:

We have (briefly) considered this case in the course.
In this case, the value of X is taken from the main query (i.e., from the outside of the subquery).