Average selling price for product 1 = ((100 * 5) + (15 * 20)) / 115 = 6.96 Average selling price for product 2 = ((200 * 15) + (30 * 30)) / 230 = 16.96 三、SQL 语句 SELECTa.product_id,ROUND(SUM(b.price*a.units)/SUM(a.units),2)ASaverage_priceFROM(SELECTDISTINCTproduct_...