Lets say after a basic query in MDX my output was 100 rows. If I want to limit to top 10 rows, I can use topcount. But, this usage of Topcount will fetch entire 100 rows from database and then pick the top 10 from it.
I wonder if there is any other possible way to fetch top ten rows directly from database?
Related
I am learning SQL. I have a Select-From command and the output result is limited to 25 rows. I would like to increase the number of rows to say 50 or 75 rows displayed. What syntax do I include in my Select - From code to make this possible?
I tried typing 50 in front of the Select * Command.
If you mean limiting query result, depending on your database you can use some keywords.
For example, for SQL SERVER you can get only first 50 rows via the command below:
select top 50 * from yourTable;
But if you are limiting your output display via an editor/IDE, you need to check manual of it.
I am trying to build a stored procedure where I am able to extract data in bit size piece.
For example, if I have 1000 rows of data, I need to get it in batches of maybe first 10 or 100 and in the next run the next 10 or 100.
SELECT TOP 100 will only keep giving the first 100 rows but will ignore anything else.
Thanks,
Vicky
In PostgreSQL: To retrieve 100 rows using an SQL query we can use LIMIT 100.
Is there a way to retrieve first 100 rows and later the next 100 like doing some kind of pagination? i.e.
if I do something like:
SELECT ..... LIMIT 100;
and later execute a command like:
SELECT ... LIMIT 100
I could get the next 100 rows to the previous retrieval of 100 rows and so on?
Thanks in advance
Yes, you need to use limit combined with offset. You can find more details here
select * from table LIMIT 100 OFFSET 100*0 --first 100
select * from table LIMIT 100 OFFSET 100*1 --second 100
I am trying to analyse a sqllite database and I use these data for a bar chart. I will count and do the avg of age group by each value in each column, in this case Class with the limit of only first 100 distinct values.
An example of this table:
Age Class
25 Worker
30 Student
48 Spy
I use LIMIT 100 to limit the result. To add more information for user, I want to let user know the number of values didn't get in account and the hidden rows, is there anyway to achieve this?
Simple solution: I am not very familiar with sql so I think to do two queries, with and without LIMIT, count the number of rows and substrat each other to find the answer. But because I have 42 columns so I would be very happy if I can have another solution.
If you want all but the first 100 rows, you can combine LIMIT with OFFSET.
select * from test01 LIMIT 1000000 OFFSET 100;
I have a list of 1000 records, and I shown there 1000 records on page load using display tag.
I enabled sorting on some columns, and when I click on the table header to sort, display tag is making a database call and loading all 1000 records again.
How can we restrict to make database calls on sorting for display tag?
Because, we have loaded all the 1000 records, so could we make use of those list without loading the records again?
You are missing a fundamental: Pagination.
You should not load 1000 records at once; load 10 records at once instead (assuming 10 records is what you show in a page), and load the other 10 when changing page / sorting.
Filter them directly in the query (if you are using queries), for example, selecting page 3 (results from 21 to 30) in a query to a minimal "person table", ordered by name, would result it the following SQL:
Oracle
SELECT id, name, age
FROM ( SELECT id, name, age
FROM table_person
ORDER BY name )
WHERE ROWNUM BETWEEN 21 and 30
PostgreSQL
SELECT id, name, age
FROM table_person
ORDER BY name
LIMIT 10
OFFSET 20
and so on.
Be sure to read the documentation related to your database, and simply use query parameters to specify order by, starting row and ending row values.
you can use setFirstResults(), setMaxResults(),instead unnecessarily load all 1000 records.
divde per page max result shown 10 records only, and setFirstResult is restricted records first 5 from your records list.
Criteria cr= database_session.createCriteria(Records.class);
cr.addOrder(Order.desc("Recordsdate"));
cr.setFirstResult(5);
cr.setMaxResults(10);
all_records_list = (List<Records>) cr.list();