How to move a non-ojs database to the ojs database؟

Dear Colleague;
I have a non-OJS website: (ijfs.ir) now I wanted to move it into an OJS system. Now i need to know how can I transfer my database which is SQL into OJSdatabase?

thanks a lot
I’m waiting for your kind reply.

It is possible to use import tools to import volumes, issues and ither high level objects, but I think it is not possible just convert a database.

Thanks for your fast response.
so would you please help me to know the way of importing volumes, issues and other high-level objects?
Is it possible to import reviewers’ history to ojs?
for example, I have a table by name issue in my PHPMyadmin and also in my ojs PHPmyadmin, now I can import it and delete the old issue table in ojs or i must create same rows and columns? i dont really know how could i have my tables in ojs and its really connected to ojs site?

and of course i used issue importing menu and upload my issue XML file which i export from my phpmyadmin but this error was shown: Element ‘pma_xml_export’: No matching global declaration available for the validation root.
Do you suggest me to importing SQL files or XML files or others?

Hi. I know nothing about your current CMS, but I thing, it is impossible just export something from phpmyadmin and import into OJS. You can read about what OJS expect from files with metadata and data (pdf files can be encoded in xml) ans prepare data from your current system.

Have you looked at the Articles and Issues import/export?
https://docs.pkp.sfu.ca/admin-guide/en/data-import-and-export#import-and-export-articles-and-issues

You will need to transform the export from your current website into the OJS-specific XML format.

This is the standard way of migrating data in batch from one system to another. Unfortunately, reviews are not currently a part of the schema.