Question

很长一段时间，我用mysql这么长时间我有大量的mySQL查询，packages表将在3个案例中加入记录。

优先级：

如果dalel有packageid。



如果会员资格表包含此dalel packageid的记录。



以上2个都没有获得默认包packageid

我的查询工作正常，但如果它会慢或对服务器内存有影响，我会徘徊这是最好的方法吗？

加入的一部分：

LEFT JOIN packages AS packages ON  (CASE 
    WHEN dalel.fixedPackageid > 0
    THEN packages.packageid = dalel.fixedPackageid
    ELSE 
        ( CASE 
            WHEN membership.packageid > 0
            THEN packages.packageid = membership.packageid
            ELSE packages.isDefualt = 1
           END)
END)

整个查询：

SELECT packages.*,
    category.category_title , user.first_name , user.last_name, user.email  , user_group.title AS group_title,
    dalel.*,
    round( (((acos(sin((".$latitude."*pi()/180)) * 
            sin((dalel.latitude*pi()/180))+cos((".$latitude."*pi()/180)) * 
            cos((dalel.latitude*pi()/180)) * cos(((".$longitude."- dalel.longitude)* 
            pi()/180))))*180/pi())*60*1.1515 
    ) * 1.609344 , 1 )  AS  distance ,
     province.province_title
     " . ( $logdUserId > 0 ? ", rating.rateid AS rated " : "" ) . "
     " . ( $logdUserId > 0 ? ", favorite.fid AS favorite " : "" ) . "
FROM dalel AS dalel
LEFT JOIN province AS province ON ( province.provinceid = dalel.stateOrProvince  )
LEFT JOIN category AS category ON (category.category_id = dalel.category_id)
LEFT JOIN user AS user  ON (user.userid = dalel.userid)
LEFT JOIN user_group AS user_group  ON (user.groupid = user_group.groupid)
LEFT JOIN membership AS membership ON (membership.dalelid = dalel.dalelid AND expireDate > '" . $timeNow . "' )                     
LEFT JOIN packages AS packages ON  (CASE 
    WHEN dalel.fixedPackageid > 0
    THEN packages.packageid = dalel.fixedPackageid
    ELSE 
        ( CASE 
            WHEN membership.packageid > 0
            THEN packages.packageid = membership.packageid
            ELSE packages.isDefualt = 1
           END)
END)  
" . ($logdUserId> 0 ? "LEFT JOIN  rating AS rating ON ( rating.userid = '" .$logdUserId. "' AND dalel.dalelid = rating.dalelid ) " : "" ) . "
" . ($logdUserId> 0 ? "LEFT JOIN  favorite AS favorite ON ( favorite.userid = '" .$logdUserId. "' AND dalel.dalelid = favorite.dalelid ) " : "" ) . "
$where
GROUP BY dalel.dalelid
$having
ORDER BY $orderBy

这是连接表条件的最佳方式，或者有更好的方法查询？

JOIN表的mysql CASE条件？

0 个答案: