How to do the pagination?

[ramya smitha]

Hi,

I have a problem with the pagination. i am getting the data to the JSP through the response from the servlet. Can anyone please help me how to do the pagination? i have thousands of records and i have to show only 14 records per page.

Thanks and Regards,
Ramya

[haitham raik]

to solve the pagination problem you may use a request parameter for page number(e.g., pageNo).
when the user enter the URL to visit the page for the first time. the page number parameter will be not exist so you will send the first 14 records. if the user clicked on the next button send the ?pageNo=1 Parameter with the request URL. if you received the pageNo=1 as a parameter you will send the 2nd 14 records.

[Stan James]

Here are some notes I took on prior discussions ... see if any of them look helpful or inspire other ideas ...

I. Repeat the query for each new request.
   Algorithm
      Client requests page 1
      Execute the query
      Return rows for page 1
      Client requests page 2
      Execute the query
      Skip rows for page 1
      Return rows for page 2
   Variation
      Most RDBMS vendors support returning a specified range of row numbers.
      Efficiency varies. May not help much when combined with "order by"
   Pro/Con
      Pro: Stateless. Nothing is cached between requests.
      Pro: Simple. Every request is the same.
      Pro: Up to date with any inserts or deletes in the database.
      Con: Database and time intensive. Might be repeating large,
           expensive queries - if users really do ever page fwd.
      Con: Not guaranteed consistent. If other processes are inserting and
           deleting rows, paging fwd or bkwd might skip rows. Fwd then Bkwd
           might not give the same rows.
   Notes   We have used this with mainframe requests where even the nastiest
           queries were fast and the server had no options for storing state.
           We have used row number schemes for client requests, and the highest
           key on a page for page forward only action.
II. Hold the query results on the server
   Algorithm
      Client requests page 1
      Execute query
      Cache complete result set or just PKeys
      Return rows for page 1
      Client requests page 2
      Get rows from cache or get PKeys from cache, rows from database
      Return rows for page 2
   Pros/Cons
      Pro: Does NOT repeat the query
      Pro: Self consistent - fwd then bkwd will give identical results
      Pro: Can share cached results if two users have identical requests
      Con: Big cache in memory or someplace close to it
      Con: Complexity for cache, time-out
III. Hold a scrolling cursor on the server
   Algorithm
      Client requests page 1
      Execute query with a cursor
      Fetch & return rows for page 1
      Client requests page 2
      Fetch & return rows for page 2
   Pro/Con
      Pro: Does not repeat the query
      Pro: Very small state - just a connection & cursor
      Pro: Self consistent
      Con: More open connections. Might hold open one db connection
           per user
      Con: What does this do to the db? Doesn't it cache rows not yet
           fetched?
      Con: Complexity for time-out