CareerCup

The field in Customer_branch are cust_id and branch. What is branch is it branch_id or branch_nm.

The query according to me should be:

SELECT cust_id from Customer_Branch CB, Deposit_branch DB
LEFT JOIN Bank_Branch ON CB.branch_id = BB.Branch_id
AND CB.cust_id = DB.cust_id

To find out the customers who made deposits in all the branches in a given city is not just possible without the date range though assuming that branch_id is IFSC code.

Something like this:
select DB.Customer_Id, count(*)
from Bank_Branch BB
left join Deposit_Branch DB on BB.Branch_NM = DB.Branch_NM
where BB.city = 'city'
and DB.Deposit_date = 'Date'
and DB.Branch_NM IS NULL
GROUP BY DB.Customer_Id
HAVING count(*) = 0

select cust_id,count(distinct branch_name) from deposit_branch group by cust_id having count(cust_id) = (select count( distinct branch_id) from bank_branch)

åHere total count of branch id should match with the count for the cust_id

select cust_id,count(distinct branch_name) from deposit_branch group by cust_id having count(cust_id) =
(select count(distinct branch_id) from bank_branch)

Here distinct total count of branch id should match with the distinct count for the cust_id in depostit_branch

select cust_id,count(distinct branch_name) from deposit_branch group by cust_id having count(distinct branch_name)= select count(distinct branch_name) from bank_branch