Introduction to SQL/2

[@kang2753]

Awesome lectures. Got better understanding of Databases from these lectures. Better to practice side by side on w3schools, where you can create your own database.

[@RahulKumar-de2rw]

31:24 awesome explanation of group by and having 🔥✨

[@gopavaramsaimadhuree520]

Awesome teaching.Very good explanation sir

[@user-nz1bj1mw9b]

An average student cannot understand these lectures . 😢

[@tejeshkonchada3971]

Answer for all supervisors(direct and indirect) of "Bob" please.

[@mahekshamsukha5212]

select D.supervisor as supervisor
from emp-super A,emp-super B,emp-super C,emp-super D
where A.person="Bob" and ((A.person=B.person or A.supervisor=B.person) and (B.person=C.person or B.supervisor=C.person) and (C.person=D.person or C.supervisor=D.person))
i have just started this course.
idk if there is some command for iteration in SQL
but as there is no such facility in relational algebra i have used such long methods
also idk if the bracket syntax is correct but it should be so

[@aayushbhatnagar1999]

@@mahekshamsukha5212 what if we don't know the size of the table. then what will the query be?

[@chandrashekarreddyasani6328]

@@aayushbhatnagar1999 i think we can import it to python and perform pandas to index you will get number and use for loop

[@ankitkumarmajhi4020]

second answer of the exercise...pls...

[@megavathmahipal7011]

@@ankitkumarmajhi4020
select B.supervisor
from emp-super A, emp-super B
where A.supervisor=B.person and A.person='Bob'

[@jamespottex5197]

Arithmetic expression are used in select clause & Comparison based expression are used in where clause

[@vickyjha7126]

Watching this at 2x speed

[@muhammadmkm3093]

Hope UA-cam had 5x too😢

[@tejale3584]

@@muhammadmkm3093 use js to manipulate the speed
that is what im doinggg👀

[@PankajSingh-mm3br]

best video

[@darshanjaviya4770]

Can anyone please explain projection which is at 13:12. I can't get the concept.

[@siddharthprasad8960]

i like this video

[@gohilvishal7818]

Where can we find this ppt/pdf??

[@dineshgoutham430]

Can any one can write queries to the assignment (supervisor table)

[@vii2sharma]

* supervisor of supervisor of bob:
select distinct e.supervisor from emp_super e, emp_super s
where s.supervisor=e.person and s.person = 'bob'
*all supervisors of bob
select distinct e.supervisor from emp_super e, emp_super s
where s.person = 'bob'

[@kevinpatel6157]

@@vii2sharma this is not a generic solution. U just made use of the fact that all entries in supervisors column are ans.
for that simply
select distinct supervisors
from emp_super
will work.

[@anshukumari2862]

why was that erronous query at 28:38

[@jamespottex5197]

Because the select clause contained a non-aggregated attribute ID which was not present in group by clause. For query to be correct all the non-aggregated attributes present in the select clause must be a subset of the attributes present in the group by clause...

[@praveennavin8342]

@@jamespottex5197 can you please explain elaborately

[@archan_pandya]

15:00

[@geetusharma3923]

at 21:38 instance ,
(not unknown)= unknown seems incorrect .
wont it be (not unknown )= known ??

[@kesavsivakumar4869]

The result will be unknown since the u r doing NOT operation on an unknown value

[@rajdeepghosh6435]

6:00

[@suryasikharej908]

I cannot understand the null values concept.

[@aanandk2591]

Watch this at 1.5x , Thank me later