When you test a new module, you need to create many test orders in order to ensure that the module works without any troubles before enabling for customers. Magento 2 Delete Order extension the perfect solution to delete all test orders which can make you confused.

Clearing all orders, shipments, transactions etc.:

[color=#393318][size=2][font=Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif][php]SET FOREIGN_KEY_CHECKS = 0;

TRUNCATE `sales_order`;

TRUNCATE `sendfriend_log`;

TRUNCATE `wishlist`;

TRUNCATE `report_event`;



ALTER TABLE `sales_order` AUTO_INCREMENT=1;

ALTER TABLE `sendfriend_log` AUTO_INCREMENT=1;

ALTER TABLE `wishlist` AUTO_INCREMENT=1;

ALTER TABLE `report_event` AUTO_INCREMENT=1;[/php][/font][/size][/color]

Tested in Magento 2.1.0
Be safe : make a backup of your sql first.
Use the sql below according to your needs :

[color=#242729][size=2][font=Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif][php]SET FOREIGN_KEY_CHECKS=0;



# Clean order history

TRUNCATE TABLE `sales_bestsellers_aggregated_daily`;

TRUNCATE TABLE `sales_bestsellers_aggregated_monthly`;

TRUNCATE TABLE `sales_bestsellers_aggregated_yearly`;



# Clean order infos

TRUNCATE TABLE `sales_creditmemo`;

TRUNCATE TABLE `sales_creditmemo_comment`;

TRUNCATE TABLE `sales_creditmemo_grid`;

TRUNCATE TABLE `sales_creditmemo_item`;

TRUNCATE TABLE `sales_invoice`;

TRUNCATE TABLE `sales_invoiced_aggregated`;

TRUNCATE TABLE `sales_invoiced_aggregated_order`;

TRUNCATE TABLE `sales_invoice_comment`;

TRUNCATE TABLE `sales_invoice_grid`;

TRUNCATE TABLE `sales_invoice_item`;

TRUNCATE TABLE `sales_order`;

TRUNCATE TABLE `sales_order_address`;

TRUNCATE TABLE `sales_order_aggregated_created`;

TRUNCATE TABLE `sales_order_aggregated_updated`;

TRUNCATE TABLE `sales_order_grid`;

TRUNCATE TABLE `sales_order_item`;

TRUNCATE TABLE `sales_order_payment`;

TRUNCATE TABLE `sales_order_status_history`;

TRUNCATE TABLE `sales_order_tax`;

TRUNCATE TABLE `sales_order_tax_item`;

TRUNCATE TABLE `sales_payment_transaction`;

TRUNCATE TABLE `sales_refunded_aggregated`;

TRUNCATE TABLE `sales_refunded_aggregated_order`;

TRUNCATE TABLE `sales_shipment`;

TRUNCATE TABLE `sales_shipment_comment`;

TRUNCATE TABLE `sales_shipment_grid`;

TRUNCATE TABLE `sales_shipment_item`;

TRUNCATE TABLE `sales_shipment_track`;

TRUNCATE TABLE `sales_shipping_aggregated`;

TRUNCATE TABLE `sales_shipping_aggregated_order`;



# Clean cart infos

TRUNCATE TABLE `quote`;

TRUNCATE TABLE `quote_address`;

TRUNCATE TABLE `quote_address_item`;

TRUNCATE TABLE `quote_id_mask`;

TRUNCATE TABLE `quote_item`;

TRUNCATE TABLE `quote_item_option`;

TRUNCATE TABLE `quote_payment`;

TRUNCATE TABLE `quote_shipping_rate`;



# Reset indexes (if you want your orders number start back to 1

TRUNCATE TABLE sequence_invoice_1;

TRUNCATE TABLE sequence_order_1;

TRUNCATE TABLE sequence_shipment_1;

TRUNCATE TABLE sequence_creditmemo_1;





SET FOREIGN_KEY_CHECKS=1;

[/php][/font][/size][/color]

DO NOT TRUNCATE / EMPTY THE FOLLOWING :

• sales_order_status
  
• sales_sequence_meta
  
• sales_sequence_profile
  
• sales_order_status_label
  
• sales_order_status_state
  

You can delete order via programmatically:

[color=#242729][size=2][font=Consolas, Menlo, Monaco, "Lucida Console", "Liberation Mono", "DejaVu Sans Mono", "Bitstream Vera Sans Mono", "Courier New", monospace, sans-serif][php]$objectManager = \Magento\Framework\App\ObjectManager::getInstance();



$order = $objectManager->create('Magento\Sales\Model\Order')->getCollection()



->addFieldToFilter('entity_id', (array) $orderIds);



foreach ($orders as $o) {



//load order object - I know it's not ok to use load in a loop but it 



should be ok since it's a one time script



$order = Mage::getModel('sales/order')->load($o->getId());



//delete all order items



$items = $order->getAllItems();



foreach ($items as $item) {



    $item->delete();



}



$invoices = $order->getInvoiceCollection();



foreach ($invoices as $invoice){



//delete all invoice items



    $items = $invoice->getAllItems();



    foreach ($items as $item) {



        $item->delete();



    }



    //delete invoice

    $invoice->delete();

}



$creditnotes = $order->getCreditmemosCollection();

foreach ($creditnotes as $creditnote){



  //delete all creditnote items



    $items = $creditnote->getAllItems();

    foreach ($items as $item) {

        $item->delete();

    }

    //delete credit note

    $creditnote->delete();

}

$shipments = $order->getShipmentsCollection();

foreach ($shipments as $shipment){



  //delete all shipment items



    $items = $shipment->getAllItems();

    foreach ($items as $item) {

        $item->delete();

    }

    //delete shipment

    $shipment->delete();

}[/php][/font][/size][/color]

Or you can make it become easy by in use this simple extension available for FREE for Magento 2 here: -> https://www.mageplaza.com/magento-2-delete-orders/

or download FREE Delete orders for Magento 2 on GitHub