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  • mysql 自我连接表

    SELECT
        count(*) AS count 
    FROM
        aliexpress_online_listing_update AS t1
        INNER JOIN (
        SELECT
            t2.id,
            t2.listing_online_id,
            t2.item_id,
            t2.sku,
            t2.shop_id,
            t2.type,
            MAX( t2.created_at ) AS maxdate 
        FROM
            aliexpress_online_listing_update AS t2 
        WHERE
            t2.push_status = 0 
        GROUP BY
            t2.listing_online_id,
            t2.item_id,
            t2.sku,
            t2.shop_id,
            t2.type 
        ) AS t3 ON t1.listing_online_id = t3.listing_online_id 
        AND t1.item_id = t3.item_id 
        AND t1.sku = t3.sku 
        AND t1.shop_id = t3.shop_id 
        AND t1.type = t3.type 
        AND t1.created_at = t3.maxdate;

    表   aliexpress_online_listing_update 先查询最大创建时间的表

    SELECT
            t2.id,
            t2.listing_online_id,
            t2.item_id,
            t2.sku,
            t2.shop_id,
            t2.type,
            MAX( t2.created_at ) AS maxdate 
        FROM
            aliexpress_online_listing_update AS t2 
        WHERE
            t2.push_status = 0 
        GROUP BY
            t2.listing_online_id,
            t2.item_id,
            t2.sku,
            t2.shop_id,
            t2.type 
    然后与原来的表进行二次连接
     
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  • 原文地址:https://www.cnblogs.com/kevin-yang123/p/14764014.html
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