SELECT customer_id, MIN(purchase_date) AS first_purchase,
SUM(CASE WHEN purchase_date BETWEEN MIN(purchase_datepurchase_date BETWEEN MIN(purchase_date) AND DATETIME_ADD(MIN(purchase_date), INTERVAL 2 YEAR THEN spendEND) AS 24_mnth_total
我要修改的表是"purchase order details“,我需要的所有数据都在这个表中,用数量和单位成本的乘积填充新列(Total Price)。ALTER TABLE [purchase order details]details].quantity * [purchase order deta