可以請你在調整查詢

Question

幫助這個查詢需要大約45秒至1分鐘爲25000個records.I需要一個替代區分 條件expirydate場

SELECT a.id, 
     a.name, 
     a.lastname, 
     a.plainpass, 
     a.email, 
     a.custom_usertype, 
     a.custom_registertype, 
     a.content_state, 
     a.year, 
     a.bflag, 
     a.block, 
     a.trail_expiry, 
     a.subscribe_date, 
     CASE a.custom_usertype 
      WHEN (5) 
      THEN 
      (IF(
        (SELECT custom_usertype 
         FROM skw_users 
         WHERE id = a.parent_id AND custom_usertype = 11) = 11 
       AND a.custom_registertype = "subscribed", 
       (SELECT DATE_FORMAT(prod.expiry_date, "%Y-%m-%d") 
        FROM skw_product prod 
        WHERE prod.student_id = a.id 
        ORDER BY prod.expiry_date DESC 
        LIMIT 1), 
       IF(
         (SELECT custom_usertype 
          FROM skw_users 
          WHERE id = a.parent_id AND custom_usertype = 10) = 
          10 
        AND a.custom_registertype = "subscribed", 
        (SELECT DATE_FORMAT(prod.expiry_date, "%Y-%m-%d") 
         FROM skw_product prod 
         WHERE prod.User_id = a.parent_id 
        ORDER BY prod.expiry_date DESC 
         LIMIT 1), 
        (SELECT DATE_FORMAT(trail_expiry, "%Y-%m-%d") 
         FROM skw_users 
         WHERE id = a.parent_id)))) 
      WHEN (3) 
      THEN 
      (IF(a.custom_registertype = "subscribed", 
       (SELECT DATE_FORMAT(prod.expiry_date, "%Y-%m-%d") 
        FROM skw_product prod 
        WHERE prod.User_id = a.parent_id 
        ORDER BY prod.expiry_date DESC 
        LIMIT 1), 
       (SELECT DATE_FORMAT(trail_expiry, "%Y-%m-%d") 
        FROM skw_users 
        WHERE id = a.parent_id))) 
      ELSE 
      (IF(a.custom_registertype = "subscribed", 
       (SELECT DATE_FORMAT(prod.expiry_date, "%Y-%m-%d") 
        FROM skw_product prod 
        WHERE prod.User_id = a.id 
        ORDER BY prod.expiry_date DESC 
        LIMIT 1), 
       (SELECT DATE_FORMAT(trail_expiry, "%Y-%m-%d") 
        FROM skw_users 
        WHERE id = a.id))) 
     END 
      AS expiry_date_n, 
     CASE a.custom_usertype 
      WHEN (5) 
      THEN 
      (SELECT TRIM(NAME) 
       FROM skw_users 
       WHERE id = a.parent_id AND custom_usertype = 10) 
      WHEN (3) 
      THEN 
      (SELECT TRIM(NAME) 
       FROM skw_users 
       WHERE id = a.parent_id) 
      WHEN (10) 
      THEN 
      (SELECT TRIM(NAME) 
       FROM skw_users 
       WHERE id = a.id AND a.custom_usertype = 10) 
     END 
      AS schoolname 
    FROM `skw_users` AS a 
     INNER JOIN 
      skw_user_usergroup_map AS map2 
     ON map2.user_id = a.id 
WHERE map2.group_id = 2 
GROUP BY a.id 
ORDER BY trim(a.name) ASC 

這個查詢需要大約45秒至1分鐘的25000個records.I需要一種替代情況下expirydate字段 條件

Answer 1

試穿Primary Key列，它是a.id和要在其上施加的情況下是a.custom_usertype

列添加索引

希望這會加快查詢的執行速度:)