Maintaining search form input

Question

I'm building a CRUD application and need to implement two forms of search:

The basic search function accepts a keyword and searches every column in the database table for that particular keyword. The search keyword is sent as an URL-parameter in the form www.website.com/category?q=keyword. Nothing too special here...

In the advanced search form users can specify up to 5 keywords and for each of those they can select a column from the database table which needs to be searched for this keyword. In short: the advanced search form takes up to 5 keyword-column pairs. This form gets submitted via POST (because i want to avoid hitting limitations on maximum number of URL-characters).

The results need to be paginated, showing 10 records per page. I've searched for pagination classes online, but they all fetch the total amount of records in the database table, and then return the selection that needs to be displayed for that page. Because I'm working with a large set of data here, I can't afford to do it this way.

This lead me to create my own pagination class, which takes the requested page number (and if applied, the $_GET and $_POST parameters from the search forms). Based on that it calculates the total number of results, calculates the total number of pages, decides whether there's a 'previous' and 'next' page... It also returns an SQL statement (with LIMIT and OFFSET values) to be executed by the particular Model (using my own MVC architecture (aka no framework)). This allowed me to only fetch the results for the requested page.

Problem: when the user navigates through the pages (aka clicking 'previous' or 'next' buttons), the $_POST data is lost. However, these values are needed in order to get the results for another page.

This particular problem made me think about the search forms on forums. I submitted a query on one of them and noticed a search ID getting appended to the URL: example.com/forum/search.php?searchid=5672532

This means that the form data is being kept somewhere, somehow... and I'm thinking what the best option might be, from most to least plausible: - Database table where each search input gets saved for e.g. 30 minutes - Sessions - Files (hidden fields are obviously not an option, because they need a form submit button to be pressed in order to get sent with the request)

I'd like to here your opinions on this, some of you must have encountered this problem already...

Answer 1

Saving the search parameters in JSON or URL encoded in a database for a set amount of time (have an expiry column) seems the best solution.

Note that in that way, you'll need to query the database over and over, with different LIMIT clauses.