jwei.aiesec.tju
BAN USERselect name from Candidate where ID in
(select candidate_ID from Vote
group by candidate_ID having count(*) in
(select max(c) from
(select count(*) c from Vote group by candidate_ID))
select name from Candidate where ID in
(select candidate_ID from Vote
group by candidate_ID having count(*) in
(select max(c) from
(select count(*) c from Vote group by candidate_ID))
select a1, a2 from table_name
minus
(select a1, a2 from table_name
group by a1, a2
having count(*)>=2)
Good thinking, I think you need to put the last row outside of a subquery, as:
select * from
(select customer_id
from (select customer_id,sum(expenses) as exp
from table_name
group by customer_id,product_id)
orderby exp )
where rownum<=5
Good answer, but this doesn't work in Oracle.
Need to use "where ROWNUM=1" in Oracle instead of "limit 1".
I think this will work:
SELECT user FROM Table GROUP BY user HAVING COUNT(user) =
(SELECT max(c) FROM (SELECT COUNT(user) c FROM Table GROUP BY user))
1. Binary B-tree style indexing
- jwei.aiesec.tju September 26, 20142. B-Tree indexing
3. Inverted list indexing
4. Memory resident table
5. Table indexing
A view consists of rows and columns just like a table. The difference between a view and a table is that views are definitions built on top of other tables (or views), and do not hold data themselves.
Stored procedure is a grouped SQL statements that forms a logical unit and performs a specific task. It is used to encapsulate a set of operations.
There are a number of common reasons for slow-running queries and updates:
Slow network communication.
Inadequate memory in the server computer, or not enough memory available for SQL Server.
Lack of useful statistics
Lack of useful indexes.
Lack of useful indexed views.
Lack of useful data striping.
Lack of useful partitioning.