mysql中多个left join子查询写法以及别名用法

Posted 2020-10-12 L先生AI课堂

不多说 直接上语句  

SELECT

    a.id,

    a.thumbNail,

    a. NAME,

    a.marketPrice,

    a.memberPrice,

    a.personName,

    a. STATUS,

    a.recieveOrderDate,

    a.trackNumber,

    a.contact,

    a.reportSendDate,

    b.trackNumber,

    a.reportDownloadPath

FROM

    (

        SELECT

            od.id,

            ps.thumbNail,

            ps. NAME,

            od.marketPrice,

            od.memberPrice,

            od.personName,

            od. STATUS,

            od.recieveOrderDate,

            ol.trackNumber,

            ol.contact,

            od.reportSendDate,

            od.reportSendOrderLogisticId,

            od.reportDownloadPath

        FROM

            orders.order_detail od

        LEFT JOIN orders.order_logistics ol ON od.recieveOrderLogisticId = ol.id

        LEFT JOIN orders.product_snapshot ps ON od.productSnapShotId = ps.id

        WHERE

            od.valid = TRUE

        AND ol.valid = TRUE

        AND od.orderId =?

    ) a

LEFT JOIN (

    SELECT

        ol.trackNumber,

        od.id

    FROM

        orders.order_detail od

    LEFT JOIN orders.order_logistics ol ON od.reportSendOrderLogisticId = ol.id

    WHERE

        od.valid = TRUE

    AND ol.valid = TRUE

    AND od.orderId =?

) b ON a.id = b.id

 

 

ps：解释下 对于mysql中的语句，牵扯到左查询时  可以用left join关联  但一般对于不知道什么时候起别名 什么时候用括号的老铁们 真实头疼  所以发个模板 剩下的根据自己的业务具体实施。