How to update existing data by selecting key record in form?

I want to allow users to select key sets of fields that will bring up the existing data and allow them to complete other fields in the form.

Do you want to show/hide fields based on some other fields? If yes, please refer to this guide:

https://www.jotform.com/help/316-How-to-Show-or-Hide-Fields-Base-on-User-s-Answer

If you are referring to something else could you please give us more information on your requirement.

Looking forward to your requirements.

Thanks.

What I want is to have the users enter a few key fields and then have the form retrieve all the data associated with those fields.  Then they can update in form view the data and submit.

You can have a look at our Spreadsheet to Form widget:

https://www.jotform.com/widgets/spreadsheet-to-form

The Spreadsheet to Form widget allows you to upload your spreadsheet to your form and use the values you have on the spreadsheet to pre-populate your form. By using a unique code that is present in every row of your spreadsheet, you can access that specific row that matches the unique code. The values are automatically populated on your form fields, as long as the spreadsheet column headings match your form field labels.

Let us know if suits your needs.

Thanks

No, the Spreadsheet to form widget will not work because the key fields that need to be used are numeric.

My request is that now that the database associated with the form has been populated, I want my users to be able to select records based on specific fields to bring up all the information about that record and then be able to update the fields in that record and submit/save the updates, similar to an ACCESS Database.

Unfortunately, you cannot update records directly to your database but you can use the edit link to update the user's response which would be recorded in your account.

You can use an edit link. If you want to let your users modify your form after submission. It is possible with {edit_link} function. Please, check the guide below for more information:

https://www.jotform.com/help/40-How-to-Let-Users-Update-Their-Form-Submissions-at-a-Later-Date

Once they have updated the responses in the JotForm then you can use webhook to call your database to make an entry into it.

Guide: https://www.jotform.com/help/126-How-to-send-Submissions-to-Your-MySQL-Database-Using-PHP

If you have any questions or issues, please do not hesitate to contact us. We will be glad to assist you.

Thanks.