Custom Pagination in datatable - sql

Question

I have a web application in which I get data from my database and show in a datatable. I am facing an issue doing this as the data that I am fetching has too many rows(200 000). So when I query something like select * from table_name;
my application gets stuck.
Is there a way to handle this problem with JavaScript?
I tried pagination but I cannot figure how would i do that as datatable creates pagination for already rendered data?
Is there a way through which I can run my query through pagination at
the backend?

Answer 1

I have come across the same problem when working with mongodb and angularjs. I used server side paging. Since you have huge number of records, You can try using the same approach.
Assuming a case that you are displaying 25 records in one page.
Backend:
Get the total count of the records using COUNT query.
select * from table_name LIMIT 25 OFFSET
${req.query.pageNumber*25} to query limited records based on the page number;
Frontend:
Instead of using datatable, display the data in HTML table it self.
Define buttons for next page and previous page.
Define global variable in the controller/js file for pageNumber.
Increment pageNumber by 1 when next page button is clicked and
decrement that by 1 when prev button is pressed.
use result from COUNT query to put upper limit to pageNumber
variable.(if 200 records are there limit will be 200/25=8).
So basically select * from table_name LIMIT 25 OFFSET
${req.query.pageNumber*25} will limit the number of records to 25. when req.query.pageNumber=1, it will offset first 25records and sends next 25 records. similarly if req.query.pageNumber=2, it will offset first 2*25 records and sends 51-75 records.

Answer 2

There are two ways to handle.
First way - Handling paging in client side
Get all data from database and apply custom paging.
Second way - Handling paging in server side
Every time you want to call in database and get records according to pagesize.

Answer 3

You can use LIMIT and OFFSET constraints for pagination in MySQL. I understand that at a time 2 lacs data makes performance slower. But as you mention that you have to use JS for that. So make it clear that if you wants js as frontend then it is not going to help you. But as you mention that you have a web application, If that application is on Node(as server) then I can suggest you the way, which can help you a lot.
use 2 variables, named var_pageNo and var_limit. Now use the row query of mysql as
select * form <tbl_name> LIMIT var_limit OFFSET (var_pageNo * var_limit);
Do code according to this query. Replace the variable with your desire values. This will make your performance faster, and will fetch the data as per your specified limit.
hope this will helpful.