我的SQL查询更新了数据库中的所有库存,但是它不能非常有效地工作,有时会出现504个超时错误。该代码工作正常。我怎样才能使其更好地工作。
PS :请忽略缺少准备好的陈述,我将在以后添加。
有关表的某些信息(Wordpress Woocommerce插件默认表):
wp_posts :该表包括帖子。 (帖子可以是产品,也可以是产品变体。例如,产品是蝴蝶T恤,产品变体是红色的蝴蝶T恤)。
wp_postmeta :此表包含有关帖子的元信息。例如,如果某产品变体有库存,或者它是什么颜色,或者它是什么尺寸。
//This array gives, which products are there, and their respective categories.
$allProducts = array("Fermuarlı Kapşonlu Sweatshirt" => "'2653','2659'","Kapşonlu Sweatshirt" => "'2646','2651'","Sweatshirt" => "'2644','2650'","Kadın Tişört" => "'2654','2656'","Atlet" => "'2655','2657'","Tişört" => "'2643','2304'");
//Below arrays gives information about, which product variations are out of stock.
$tisort_OutOfStock =array();
$atlet_OutOfStock =array("all_colors"=>"'3xl','4xl','5xl'");
$kadin_tisort_OutOfStock =array("all_colors"=>"'xxl','3xl','4xl','5xl'");
$sweatshirt_OutOfStock =array("beyaz"=>"'xxl','3xl','4xl','5xl'","kirmizi"=>"'xxl','3xl','4xl','5xl'","bordo"=>"'5xl'","antrasit"=>"'5xl'");
$kapsonlu_sweatshirt_OutOfStock =array("gri-kircilli"=>"'5xl'");
$fermuarli_kapsonlu_sweatshirt_OutOfStock =array("gri-kircilli"=>"'5xl'","siyah"=>"'5xl'");
//Reset stocks before updating.
$resetStocks = "UPDATE wp_postmeta set meta_value = 'instock' where meta_key = '_stock_status'";
$wpdb->query($resetStocks);
echo "Stoklar are reseted<br>";
//Foreach product, foreach color, update if product doesn't have stock.
foreach( $allProducts as $key => $urun ){
switch ($key) {
case "Kadın Tişört": $tempArray = $kadin_tisort_OutOfStock; break;
case "Fermuarlı Kapşonlu Sweatshirt": $tempArray = $fermuarli_kapsonlu_sweatshirt_OutOfStock; break;
case "Kapşonlu Sweatshirt": $tempArray = $kapsonlu_sweatshirt_OutOfStock; break;
case "Sweatshirt": $tempArray = $sweatshirt_OutOfStock; break;
case "Atlet": $tempArray = $atlet_OutOfStock; break;
case "Tişört": $tempArray = $tisort_OutOfStock; break;
}
foreach( $tempArray as $color => $size ){
$query = "UPDATE wp_postmeta set meta_value = 'outofstock' where meta_key = '_stock_status' and post_id in
(
select post_id from (select * from wp_postmeta) AS X where meta_key = 'attribute_pa_beden' and meta_value in (".$size.")
and post_id in (select post_id from (select * from wp_postmeta) AS Y where meta_key = 'attribute_pa_renk' and ((meta_value = '".$color."') OR ('".$color."' = 'all_colors')))
and post_id in (select id from wp_posts where post_type = 'product_variation' and post_parent in (select object_id FROM wp_term_relationships where term_taxonomy_id in (".$urun.")))
)";
global $wpdb;
$updatedRowCount = $wpdb->query($query);
}
}
答案 0 :(得分:1)
SELECT post_id
from
(
SELECT *
from wp_postmeta
) AS X
where ...
->
SELECT post_id
FROM wp_postmeta
WHERE ...
(子查询只会减慢速度。)
and post_id in (
SELECT post_id
使用IN ( SELECT ... )
代替JOIN
。
除了这些技巧外,请参阅我的tips关于改进postmeta模式的信息。
答案 1 :(得分:1)
首先使用键SELECT
:
SELECT post_id
from
(
SELECT *
from wp_postmeta
) AS X
where meta_key = 'attribute_pa_beden'
and meta_value in (".$size.")
and post_id in (
SELECT post_id
from
(
SELECT *
from wp_postmeta
) AS Y
where meta_key = 'attribute_pa_renk'
and ((meta_value = '".$color."')
OR ('".$color."' = 'all_colors'))
)
and post_id in (
SELECT id
from wp_posts
where post_type = 'product_variation'
and post_parent in (
SELECT object_id
FROM wp_term_relationships
where term_taxonomy_id in (".$urun.")))
)";
是的,我知道您需要从wp_postmeta
中“隐藏” UPDATE wp_postmeta
,但是我们可以重新安排事情以提高效率。请注意,在两种情况下,如何先获取整个wp_postmeta
过滤条件?这样就无法使用任何索引,因此很麻烦。
SELECT m1.post_id
FROM wp_postmeta AS m1
JOIN wp_postmeta AS m2 USING(post_id)
JOIN wp_posts AS p2 USING(post_id)
JOIN wp_term_relationships AS tr ON p2.post_parent = tr.object_id
WHERE m1.meta_key = 'attribute_pa_beden' AND m1.meta_value in ("$size")
AND m2.meta_key = 'attribute_pa_renk' AND ( m1.meta_value = '$color'
OR '$color' = 'all_colors' )
AND p2.post_type = 'product_variation'
AND tr.term_taxonomy_id IN ($urun)
忘记UPDATE
,直到调试SELECT
。 (我可能犯了一些错误,但是看起来不是很简单吗?它将运行得更快,尤其是使用我推荐的索引时。)
带有颜色的OR
可能会被优化,所以我不必担心。
我无法预测优化器将以4个表中的哪个开始,因此需要这些索引来进行选择:
tr: (term_taxonomy_id, object_id) -- in this order
posts: (post_type, post_id) -- in this order
postmeta: (meta_key, meta_value) -- see note below
Optimizer选择要从哪个表开始后,它将依次转到其他每个表;顺序对我们来说无关紧要。这些其他索引可能会有用:
posts: (post_parent, post_id) -- in this order
postmeta: (post_id, meta_key, meta_value) -- see note below
如果meta_value
是LONGTEXT
,则它不能在索引中,因此请忽略它。 (不,不要打扰“前缀”索引。)
如果您使用的是MySQL 5.5或5.6,则meta_key
太长而无法成为索引;有关多种解决方法,请参见我的link。
EAV模式很糟糕,您正在找出原因。
返回UPDATE
的合并,添加包装器:
UPDATE wp_postmeta AS m
JOIN ( SELECT post_id
FROM ( the above query )
) AS kludge USING (post_id)
SET m.meta_value = 'outofstock'
WHERE m.meta_key = '_stock_status'