Consulta SQL que retorna a quantidade de Vendas agrupadas por dia juntamente com os SKU + e Quantidades no Magento 2, no exemplo abaixo estamos considerando apenas os pedidos com state processing
SELECT date(soi.created_at) as 'date',
count(*) as 'total orders',
sum(qty_ordered) as 'total itens',
(
SELECT
GROUP_CONCAT(
DISTINCT CONCAT(soi.sku,':',soi.qty_ordered )
ORDER BY soi.item_id
SEPARATOR '|'
)
) as 'sku and qty'
FROM sales_order so
INNER JOIN sales_order_item soi on so.entity_id = soi.order_id
WHERE so.state = 'processing'
GROUP BY date(soi.created_at)
ORDER BY date(soi.created_at) DESC