group_concat()会计算哪些行属于同一组,将属于同一组的列显示出来,group by指定的列进行分组。
例如:
-- 根据物流订单id查询所有物流订单,车源订单,车辆信息(多条数据合并为一条数据,英文逗号隔开)
SELECT
a.id AS logisOrderId,
a.logistics_order_code AS logisOrderCode,
a.logis_order_sum_fee AS logisOrderSumFee,
GROUP_CONCAT(b.id) AS carSourceOrderId,
b.start_city_name AS startCityName,
b.end_city_name AS endCityName,
b.start_city_id AS startCityId,
b.end_city_id AS endCityId,
GROUP_CONCAT(b.buyer_id) AS buyerId,
GROUP_CONCAT(b.buyer_name) AS buyerName,
GROUP_CONCAT(b.buyer_phone) AS buyerPhone,
GROUP_CONCAT(c.id) AS carSourceOrderItemId,
GROUP_CONCAT(d.car_brand) AS carBrand,
GROUP_CONCAT(d.car_type) AS carType,
GROUP_CONCAT(d.colour) AS carColor,
sum(c.insurance_fee) AS insuranceSumFee,
sum(c.actual_fee) AS actualSumFee,
GROUP_CONCAT(d.car_id) AS carId
FROM
t_ims_logistics_order a
LEFT JOIN t_ims_carsource_order b ON a.id=b.logistics_order_id
LEFT JOIN t_ims_carsource_order_item c ON b.id = c.car_source_order_id
LEFT JOIN t_ims_car d ON c.logistics_car_id = d.id
WHERE
a.id=11
GROUP BY a.id
合并前:两条数据
合并后:一条数据
链接:https://blog.csdn.net/mary19920410/article/details/76545053