Question

我有以下查询。

select entity_id ,parent_id,name as label , url_key as name from magento_catalog_category_flat_store_1 where entity_id IN(select
            distinct flat.parent_id from magento_catalog_category_flat_store_1 as flat RIGHT JOIN sohyper_region_activity as act on flat.entity_id = act.activity_id )

由于IN子句，上述查询会降低性能。谁能告诉我如何在这个查询中用JOIN替换IN子句？

感谢。

Answer 1

SELECT m.entity_id ,m.parent_id,m.name as label , m.url_key as name 
FROM magento_catalog_category_flat_store_1 as m 
INNER JOIN magento_catalog_category_flat_store_1 as flat
    ON m.entity_id = flat.parent_id
RIGHT JOIN sohyper_region_activity as act on flat.entity_id = act.activity_id

Answer 2

是试试这个

SELECT T1.entity_id, T1.parent_id, T1.name As Label, T1.url_key As Name 
FROM magento_catalog_category_flat_store_1 T1 
INNER JOIN magento_catalog_category_flat_store_1 as T2 ON 
           T1.entity_id = T2.parent_id
RIGHT JOIN sohyper_region_activity as T3 on 
           T2.entity_id = T3.activity_id

如何在mysql中用JOIN替换IN子句？

2 个答案: