Sql query

Question

Please explain below query step by step and what does it mean?

Comments

it is giving name of students securing 3rd highest marks

Answer 1

It is giving name of student who secured 3rd rank among all.

Here are two columns "Name" and "marks" in the table. and "Count" column is just for explanation.

Name	Marks	Count
A	50	5
B	78	3
C	82	2
D	99	1
E	74	4

Here same table is referenced two times. S1 is for outer query and S2 for inner query. and both are co-related subqueries. Hence for each S1 we need to check all S2.

S1 = A,50 then count = 5 (Because 50 is lesser or equal to all given marks.)

S1 = B,78 then count = 3 (because 78 is lesser or equal to 78,82,99)

S1 = C,82 then count = 2 (because 82 is lesser or equal to 82,99)

S1 = D,99 then count = 1 (because nothing is lesser than 99 only it is equal to itself in S2.marks)

S1 = E,74 then count = 4 (because 74 is lesser or equal to 74,78,82,99)

Hence we have to choose name of count =3 Which giving name of student who secured 3rd rank.

Comments

yes its 100% correct..