How can get custom table columns on product listing page using product_id of the custom table

Question

On product listing page, I need to show visitor nearest product first.

I've a marketplace site and each product have different seller and there is a custom table having seller_id and product_id column.

Here is the structure screenshot of my custom table:-

So how can i get the seller id of each product on product lsiting page so that i can dispay nearest product first?I'm trying to use joins based on product_id on product collection here:-

Class:- vendor/magento/module-catalog/Block/Product/ProductList/Toolbar.php

Method:- setCollection()

But seems,there is some problem in the joining due to which filter is not working.

My Join Code:-

$collection->addAttributeToSelect('*');
$joinType = "inner"; // join type
$where = ""; // put condition
$fields = "*"; // fields
$collection->joinTable(
            ['custom' => 'marketplace_product'],
            'custom.mageproduct_id = e.id', //also tried "entity_id" instead of "id"
            $fields,
            $where,
            $joinType
        );

        echo $collection->getSelect() ; exit;

 Not printing anything on listing page.   

So please let me know the code so that i can use the join and get the seller_id and then i can calculate nearest one.

UPDATE:-

After using like that:-

 $joinConditions = 'ust.mageproduct_id = e.entity_id';

                         $this->_collection->getSelect()->join(
                ['ust' => $this->_collection->getTable('marketplace_product')],
                $joinConditions,
                []
            )->columns("ust.seller_id");

Joining is working fine but now I'm getting "You cannot define a correlation name 'ust' more than once" problem so please help me to resolve this problem.

Waiting for your reply!

Thanks!!!

Answer 1

Used Tablename "marketplace_product" instead of using alias "mp" and it's working fine now.