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Php SQL查询运行非常慢_Php_Mysql - Fatal编程技术网
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Php SQL查询运行非常慢

php mysql

Php SQL查询运行非常慢,php,mysql,Php,Mysql,我有如下表关系： 我从php运行了以下查询，遇到了两个大问题。 1） 超出了最大内存限制 2） 已超过最大执行时间 SELECT DISTINCT venues.name, locations.location, events.event, types.type, foods.food, beverages.beverage, event_options.event_option, styles.style, space_requirements.space_requirement, fea

我有如下表关系：

我从php运行了以下查询，遇到了两个大问题。
1） 超出了最大内存限制
2） 已超过最大执行时间

SELECT DISTINCT venues.name, locations.location, events.event, types.type, foods.food, beverages.beverage, event_options.event_option, styles.style, space_requirements.space_requirement, features.feature

FROM (SELECT * FROM venues v LIMIT $offset,$limit) venues

INNER JOIN locations ON venues.location_id = locations.location_id

LEFT JOIN venue_events ON venues.venue_id = venue_events.venue_id
LEFT JOIN events ON events.event_id = venue_events.event_id

LEFT JOIN venue_types ON venues.venue_id = venue_types.venue_id
LEFT JOIN types ON types.type_id = venue_types.type_id

LEFT JOIN venue_foods ON venues.venue_id = venue_foods.venue_id
LEFT JOIN foods ON foods.food_id = venue_foods.food_id

LEFT JOIN venue_beverages ON venues.venue_id = venue_beverages.venue_id
LEFT JOIN beverages ON beverages.beverage_id = venue_beverages.beverage_id

LEFT JOIN venue_event_options ON venues.venue_id = venue_event_options.venue_id
LEFT JOIN event_options ON event_options.event_option_id = venue_event_options.event_option_id

LEFT JOIN venue_styles ON venues.venue_id = venue_styles.venue_id
LEFT JOIN styles ON styles.style_id = venue_styles.style_id

LEFT JOIN venue_space_requirements ON venues.venue_id = venue_space_requirements.venue_id
LEFT JOIN space_requirements ON space_requirements.space_requirement_id = venue_space_requirements.space_requirement_id

LEFT JOIN venue_features ON venues.venue_id = venue_features.venue_id
LEFT JOIN features ON features.feature_id = venue_features.feature_id

我使用此查询检索与每个场馆相关的所有附件。我需要在后端实现分页，所以我在子查询中使用LIMIT$offset$LIMIT。我找不到任何其他想法（查询），因此我可以获得与我现在检索的相同的结果。目前我正在使用


ini_集（'内存限制'，'-1'）


ini\u集（'max\u execution\u time'，60）

php函数忽略了这些问题，但我认为这不是最佳实践。此外，我还考虑了可能需要检索50多个场馆的所有附件的情况，对于这种情况，
max\u execution\u time=60
可能不够。

我怎样才能解决这个问题？
请帮帮我

已更新

获取的行数为（活动*类型*食品*饮料*活动选项*风格*空间要求*功能）每个场馆的行数。但对我来说有用的行数不是乘法而是和



下面是我使用
EXPLAIN
关键字运行查询后发现的结果


Array
(
    [0] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => 
            [type] => ALL
            [possible_keys] => 
            [key] => 
            [key_len] => 
            [ref] => 
            [rows] => 11
            [Extra] => Using temporary
        )

    [1] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => venue_events
            [type] => ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 4
            [ref] => venues.venue_id
            [rows] => 3
            [Extra] => Using index
        )

    [2] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => events
            [type] => eq_ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 1
            [ref] => serofero_mvb.venue_events.event_id
            [rows] => 1
            [Extra] => 
        )

    [3] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => venue_types
            [type] => ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 4
            [ref] => venues.venue_id
            [rows] => 7
            [Extra] => Using index
        )

    [4] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => types
            [type] => eq_ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 1
            [ref] => serofero_mvb.venue_types.type_id
            [rows] => 1
            [Extra] => 
        )

    [5] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => venue_foods
            [type] => ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 4
            [ref] => venues.venue_id
            [rows] => 3
            [Extra] => Using index
        )

    [6] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => foods
            [type] => eq_ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 1
            [ref] => serofero_mvb.venue_foods.food_id
            [rows] => 1
            [Extra] => Using index
        )

    [7] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => venue_beverages
            [type] => ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 4
            [ref] => venues.venue_id
            [rows] => 3
            [Extra] => Using index
        )

    [8] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => beverages
            [type] => eq_ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 1
            [ref] => serofero_mvb.venue_beverages.beverage_id
            [rows] => 1
            [Extra] => 
        )

    [9] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => venue_event_options
            [type] => ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 4
            [ref] => venues.venue_id
            [rows] => 2
            [Extra] => Using index
        )

    [10] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => event_options
            [type] => eq_ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 1
            [ref] => serofero_mvb.venue_event_options.event_option_id
            [rows] => 1
            [Extra] => 
        )

    [11] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => venue_styles
            [type] => ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 4
            [ref] => venues.venue_id
            [rows] => 1
            [Extra] => Using index
        )

    [12] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => styles
            [type] => eq_ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 1
            [ref] => serofero_mvb.venue_styles.style_id
            [rows] => 1
            [Extra] => 
        )

    [13] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => venue_space_requirements
            [type] => ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 4
            [ref] => venues.venue_id
            [rows] => 3
            [Extra] => Using index
        )

    [14] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => space_requirements
            [type] => eq_ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 1
            [ref] => serofero_mvb.venue_space_requirements.space_requirement_id
            [rows] => 1
            [Extra] => 
        )

    [15] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => locations
            [type] => eq_ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 1
            [ref] => venues.location_id
            [rows] => 1
            [Extra] => 
        )

    [16] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => venue_features
            [type] => ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 4
            [ref] => venues.venue_id
            [rows] => 7
            [Extra] => Using index
        )

    [17] => Array
        (
            [id] => 1
            [select_type] => PRIMARY
            [table] => features
            [type] => eq_ref
            [possible_keys] => PRIMARY
            [key] => PRIMARY
            [key_len] => 1
            [ref] => serofero_mvb.venue_features.feature_id
            [rows] => 1
            [Extra] => 
        )

    [18] => Array
        (
            [id] => 2
            [select_type] => DERIVED
            [table] => venues
            [type] => ALL
            [possible_keys] => 
            [key] => 
            [key_len] => 
            [ref] => 
            [rows] => 11
            [Extra] => 
        )

)





感谢您为所选列创建索引。
您需要将查询更改为以下内容：


SELECT DISTINCT venues.`name`, locations.`location`, events.`event`, types.`type`, foods.`food`, beverages.`beverage`, event_options.`event_option`, styles.`style`, space_requirements.`space_requirement`, features.`feature`


请记住，这只是代码的第一行。您需要在查询中的任何地方更改此选项


出现此错误的原因是缺少索引，通过这种方式，索引将以适当的方式定义，并且易于php区分。
根据解释输出，查询似乎已经使用主键作为索引。为什么不尝试拆分查询呢

首先，获取要显示的场馆ID（分页）

接下来，运行此查询


SELECT DISTINCT venues.name, locations.location, events.event, types.type, foods.food, beverages.beverage, event_options.event_option, styles.style, space_requirements.space_requirement, features.feature

FROM venues

INNER JOIN locations ON venues.location_id = locations.location_id

LEFT JOIN venue_events ON venues.venue_id = venue_events.venue_id
LEFT JOIN events ON events.event_id = venue_events.event_id

LEFT JOIN venue_types ON venues.venue_id = venue_types.venue_id
LEFT JOIN types ON types.type_id = venue_types.type_id

LEFT JOIN venue_foods ON venues.venue_id = venue_foods.venue_id
LEFT JOIN foods ON foods.food_id = venue_foods.food_id

LEFT JOIN venue_beverages ON venues.venue_id = venue_beverages.venue_id
LEFT JOIN beverages ON beverages.beverage_id = venue_beverages.beverage_id

LEFT JOIN venue_event_options ON venues.venue_id = venue_event_options.venue_id
LEFT JOIN event_options ON event_options.event_option_id = venue_event_options.event_option_id

LEFT JOIN venue_styles ON venues.venue_id = venue_styles.venue_id
LEFT JOIN styles ON styles.style_id = venue_styles.style_id

LEFT JOIN venue_space_requirements ON venues.venue_id = venue_space_requirements.venue_id
LEFT JOIN space_requirements ON space_requirements.space_requirement_id = venue_space_requirements.space_requirement_id

LEFT JOIN venue_features ON venues.venue_id = venue_features.venue_id
LEFT JOIN features ON features.feature_id = venue_features.feature_id

WHERE venues.id IN ( $venue_ids )



这至少应该去掉派生表
 您可能缺少索引。使用
EXPLAIN
关键字直接运行查询。在这里提供结果。我从未使用过索引，所以我不知道它的威力。谢谢你介绍
EXPLAIN
关键字，我会用谷歌搜索如何使用它。非常感谢。当您将两列连接在一起时，每列都应该具有相同的匹配数据类型，并且两列都应该被索引。它将允许mysql更快地排序和匹配行。但是添加索引后仍然存在同样的问题。好的，谢谢。我应该为上面查询中加入的所有表创建索引吗？我在所有表中创建了索引，但问题仍然存在。对不起，我不明白你的意思。谢谢你的回答，但仍然需要很多时间。超过了最大内存限制，执行时间也是如此。ob_start（）和ob_flush（）是否对这种情况有帮助。现在是尼泊尔凌晨1:13，我无法入睡。恐怕总共有52575行。这是正常的吗？所以你有10个场地开始，因为它的页码是正确的？你怎么会有5万排呢？因为每个场馆都可以有多个活动，类型等等。mysql给我的结果是5（事件）*25（类型）*15（食物），我很无助。

SELECT DISTINCT venues.name, locations.location, events.event, types.type, foods.food, beverages.beverage, event_options.event_option, styles.style, space_requirements.space_requirement, features.feature

FROM venues

INNER JOIN locations ON venues.location_id = locations.location_id

LEFT JOIN venue_events ON venues.venue_id = venue_events.venue_id
LEFT JOIN events ON events.event_id = venue_events.event_id

LEFT JOIN venue_types ON venues.venue_id = venue_types.venue_id
LEFT JOIN types ON types.type_id = venue_types.type_id

LEFT JOIN venue_foods ON venues.venue_id = venue_foods.venue_id
LEFT JOIN foods ON foods.food_id = venue_foods.food_id

LEFT JOIN venue_beverages ON venues.venue_id = venue_beverages.venue_id
LEFT JOIN beverages ON beverages.beverage_id = venue_beverages.beverage_id

LEFT JOIN venue_event_options ON venues.venue_id = venue_event_options.venue_id
LEFT JOIN event_options ON event_options.event_option_id = venue_event_options.event_option_id

LEFT JOIN venue_styles ON venues.venue_id = venue_styles.venue_id
LEFT JOIN styles ON styles.style_id = venue_styles.style_id

LEFT JOIN venue_space_requirements ON venues.venue_id = venue_space_requirements.venue_id
LEFT JOIN space_requirements ON space_requirements.space_requirement_id = venue_space_requirements.space_requirement_id

LEFT JOIN venue_features ON venues.venue_id = venue_features.venue_id
LEFT JOIN features ON features.feature_id = venue_features.feature_id

WHERE venues.id IN ( $venue_ids )