Insert data into custom table in magento 2

<?php

namespace YourNameSpace\YourModule\Helper;

use Magento\Framework\App\ResourceConnection;

class Data extends AbstractHelper
{
    private $connection;

    public function __construct(
        ResourceConnection $resourceConnection
    )
    {
        $this->connection = $resourceConnection->getConnection();
    }

    public function saveData()
    {
        $bind = [
            'column1' => $column1,
            'column2' => $column2,
            'column3' => $column3,
            'column4' => $column14,
        ];
        $this->connection->insert('your_table_name', $bind);
    }
}

You need to create models

=>Resource Model ( for connect with database)

=>Model ( get and save data)

=>Collection

You can get reference from Devdoc or

https://www.codilar.com/magento-2-models-resource-models-and-collections

https://magestore-product.gitlab.io/devdocs/internship-documentation/magento/model/

You can insert data into database using one of the below two methods

Method 1 : https://bsscommerce.com/confluence/how-to-create-insert-data-into-the-table-in-magento-2/

Method 2 :

    $objectManager = \Magento\Framework\App\ObjectManager::getInstance(); 
    $resource = $objectManager->get('Magento\Framework\App\ResourceConnection');
    $connection = $resource->getConnection();
    $tableName = $resource->getTableName('tbl_name'); //gives table name with prefix

    $sql = "Insert Into " . $tableName . " (id, name) Values ('','XYZ')";
    $connection->query($sql);

You have to create Model, ResourceModel for that. And use that model to set and save the data.

1. Model Path app/code/vendor/module/Model/Custom.php

<?php

namespace vendor\module\Model;

use Magento\Framework\Model\AbstractModel;
use vendor\module\Model\ResourceModel\Custom as 
CustomResource;

class Custom extends AbstractModel{

   protected function _construct()
   {
       $this->_init(CustomResource::class);
   }
}

2. ResourceModel Path app/code/vendor/module/Model/ResourceModel/Custom.php

<?php

namespace vendor\module\Model\ResourceModel;

use Magento\Framework\Model\ResourceModel\Db\AbstractDb;

class Custom extends AbstractDb{

    const MAINTABLE = 'custom_table';
    const ID_FIELD_NAME = 'entity_id';

    protected function _construct()
    {
        $this->_init(self::MAINTABLE,self::ID_FIELD_NAME);
    }
}

2. Controller

In your controller (app/code/vendor/module/Controller/Insertion/Add.php)

<?php

namespace vendor\module\Controller\Insertion;

use vendor\module\Model\Resourcemodel\Custom as CustomResource;
use vendor\module\Model\CustomFactory;
use Magento\Framework\App\Action\Action;
use Magento\Framework\App\Action\Context;



class Add extends Action{

    private $customFactory;

    private $customResource;

    public function __construct(
        Context $context,
        CustomFactory $customFactory,
        CustomResource $customResource
    )
    {
        parent::__construct($context);
        $this->customFactory=$customFactory;
        $this->customResource=$customResource;
    }

    public function execute()
    {
        $data=$this->getRequest()->getParams();

        $customModel=$this->customFactory->create();
        $customModel->setData($data);

        try{
            $this->customResource->save($customModel);
            $this->messageManager->addSuccessMessage('Data added successfully');

        }catch(\Exception $e){
            $this->messageManager->addErrorMessage('Data Not Added'.$e->getMessage());
        }
        $redirector= $this->resultRedirectFactory->create();
        $redirector->setPath('frontname/controller/action'); //Your path
        return $redirector;
    }
}

In this way you can insert data to the table