Question

Consider an hierarchy:

Brands –> Products –> Items –> Quantity.

Suppose there are different tables, linked as shown above, having 10,000+ rows.
I want to get all the data in the following way:

Brands –With their– Products — With their– Items — With their– Quantity.

I thought of this approach
a) Getting all records from a procedure in very basic maps
b) Iterating over those maps and linking them all in Java.

As it’s taking lot of time, is there better approach than this?

Thanks in Advance

Answer 1

Looks like you are joining tables in a relational database, so it’s natural to use SQL for this. Java is the wrong tool, and you’ll probably open yourself up to many bugs.

If there’s too much data being returned from the query, try using LIMIT, or per ffriend’s suggestion, add parameters to the query to select particular chunks of the entire result set.

If the client really needs the whole lot in one go, you can start streaming the response (I assume it’s some kind of web service you’re writing) before you’ve finished reading from the database by using a cursor. But that’s a whole lot of effort, and if your server can’t handle the data, probably the client can’t either.