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Que. Table A
Id Name Age
----------------
12 Arun 60
15 Shreya 24
99 Rohit 11

Table B
Id Name Age
----------------
15 Shreya 24
25 Hari 40
98 Rohit 20
99 Rohit 11

Table C
Id Phone Area
-----------------
10 2200 02
99 2100 01
Consider the above tables A, B and C. How many tuples does the result of the following SQL query contains?
SELECT A.id
FROM A
WHERE A.age > ALL (SELECT B.age FROM B
WHERE B. name = "arun")
a. 4
b. 3
c. 0
d. 1
Answer:3
Swati :(September 23, 2020) But relation B does not contains name = Arun..
But B realation does not contain name varun
i think answer is incorrect because there is no tuple in table b name ARUN
id also not contain 3
I think the answer should be 0 as the result of the subquery would be null and so comparing any age to null would be unknown, thus no output will be there
I think the answer should be 0
Answer is 0.
yes ans must be 0
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Deepanshu sharma :(April 10, 2022) Explanation: The meaning of “ALL” is the A.Age should be greater than all the values returned by the subquery. There is no entry with name “arun” in table B. So the subquery will return NULL. If a subquery returns NULL, then the condition becomes true for all rows of A (See this for details). So all rows of table A are selected.
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