Question

我的代码在这里添加了属于该配置文件的所有成员的总和。我是这样做的，我只想知道一些其他方法来加快速度。

我在这里有相关表格Municipality，Barangay，Purok，family_profile，family_members订购他们的关系。

    SELECT f.family_id,f.family_code,f.lname,f.fname,f.mname,f.exname,f.remark,p.*,b.*,m.*,
    (SELECT SUM(member_id!=0) from family_members WHERE family_id=f.family_id) AS MEMCOUNT
    from family_profile f
    LEFT join purok p on f.home_address=p.purok_id 
    LEFT join barangay b on p.brgy_id=b.brgy_id
    LEFT join municipality m on b.mun_id=m.mun_id
    where
    f.family_id!=0 AND
    family_code!='' 
    ORDER BY
    mun_name,brgy_name,purok_name,f.lname,f.fname

Answer 1

是，在此查询中：

SELECT 
    f.family_id,
    f.family_code,
    f.lname,
    f.fname,
    f.mname,
    f.exname,
    f.remark,
    p.*,
    b.*,
    m.*,
    (
        SELECT SUM(member_id!=0) 
        FROM family_members 
        WHERE 
            family_id = f.family_id
    ) AS MEMCOUNT
FROM family_profile f
        LEFT JOIN purok p on f.home_address=p.purok_id 
        LEFT JOIN barangay b on p.brgy_id=b.brgy_id
        LEFT JOIN municipality m on b.mun_id=m.mun_id
WHERE
    f.family_id != 0 
AND family_code != '' 
ORDER BY
    mun_name,
    brgy_name,
    purok_name,
    f.lname,
    f.fname

您正在为每个返回的行计算SUM。这不是优化的。这个想法是通过将其设为记录集来计算一次：

SELECT 
    f.family_id,
    f.family_code,
    f.lname,
    f.fname,
    f.mname,
    f.exname,
    f.remark,
    p.*,
    b.*,
    m.*,
    MEMCOUNT.cnt AS MEMCOUNT
FROM family_profile f
        LEFT JOIN purok p on f.home_address=p.purok_id 
        LEFT JOIN barangay b on p.brgy_id=b.brgy_id
        LEFT JOIN municipality m on b.mun_id=m.mun_id
        LEFT JOIN 
            (
                SELECT family_id, SUM(member_id!=0) AS cnt
                FROM family_members 
                GROUP BY family_id
            ) AS MEMCOUNT ON MEMCOUNT.family_id = f.family_id
WHERE
    f.family_id != 0 
AND family_code != '' 
ORDER BY
    mun_name,
    brgy_name,
    purok_name,
    f.lname,
    f.fname

MySQL使其更快，将成员数添加到族表

1 个答案: