Hi,

I'm looking for very general guidance (top level view) on how to
wpdatatables could help is in our particular application. This is what we are trying to accomplish:

We have a database (1 flat table) with about 5 million rows. Each row
represents data that would be imported into various pdf form fillable templates
that our client can buy from us. These pdf's are predefined forms provided by others which we cannot modify others than completing the information on them. So our work flow would look like this:

Step 1: Visitor to our site searches our database by inputting
information about themselves (Name, DOB, etc) on a form.

Step 2: Upon submitting the form a query is done against the database
and returns the rows requested from the query (multiple rows can be
returned). The rows are displayed on a second form that will allow the
visitor to select which rows are to be exported to a predefined pdf
template. The selection of that row is an action that indicates that the visitor want to purchase a pdf with the data in the row merged into the pdf.

Step 3: Upon selecting the rows and submitting the form the visitor
is directed to a payment gateway to pay for the completed forms.

Step 4: After completing payment the visitor is directed to another
form where he can submit some additional information and an email
address where the forms are to be sent.

Step 5: Upon submitting the form the data on the form is exported to
E2PDF for merging to a form template. E2PDF merges the data and emails
the form to the visitor.

I see that Formidable Forms is integrated with wpdatatables so my general questions are:

1. Can wpddatatables directly query a 5M row sql database using the back-end via a Formidable form where the visitor enters the sql dynamic variables? Or does wpdatatables have a form of some type that I can display so the visitor can enter the variables?

2. Can the query to the database be written in away to prevent any sql injections (pdo, prepared statements, parameterized queries)?

3. Can wpdatatables display those queries into a Formidable form (or other form) and use values from that table as the basis of a second query? So in my example, the initial search by the visitor returns 3 rows from the database. Each row now has a unique id number which I need to use as the unique identifier of the data that has to be merged on each of the different pdf's. So all the data from record id 1 goes on the first form,  then data from record id 2 goes on form 2 ......

Ideally I visualize this as 5 forms:

Form 1 provides input fields for the first query variables.

Form 2 displays the results of the query from Form 1 in a table. On each row of the table the visitor can select (checkbox) the rows that he wants to purchase of pdf for. The table then calculates a price of the order ( example 3 pdf's at $10 each = $30). Visitor hits a submit button.

Form 3 is the payment gateway that requires the $30 payment be made to proceed.

Form 4 Visitor verifies personal information and provides email address to send the pdf's to.

Form 5 has a table with identifying information for each form with a button for each row that when pressed generates the pdf which it then compiled (via E 2PDF) and sent to the visitor's email.

I don't need a step-by-step tutorial on how to do the above. But I
could use some broader guidance on how far you believe I can get through what I'm trying to do with your product and it's integration with Formidable Forms.

I really appreciate your feedback.