我該如何優化這個mysql查詢？我使用或操作

Question

我有這樣的MySQL查詢：

select a.goods_id, 
     a.site_id, 
     b.goods_name, 
     a.cost, 
     a.stock 
from rs_goods as a 
inner join rs_goods_multi as b 
    on a.goods_id = b.goods_id 
where a.goods_sn LIKE 'sweater005%' 
OR b.goods_name LIKE 'sweater005%'; 

，它顯示了型「ALL」，也許是「OR」的原因是，如何優化它，我不得不添加索引字段「 goods_sn'和'goods_name'。你可以看到下面的mysql捕獲。 mysql capture

Answer 1

使用UNION從查詢中刪除OR，通常可以獲得更好的結果，因爲每個查詢都可以有效地使用單個索引。

select a.goods_id, 
     a.site_id, 
     b.goods_name, 
     a.cost, 
     a.stock 
from rs_goods as a 
inner join rs_goods_multi as b 
    on a.goods_id = b.goods_id 
where a.goods_sn LIKE 'sweater005%' 
UNION 
select a.goods_id, 
     a.site_id, 
     b.goods_name, 
     a.cost, 
     a.stock 
from rs_goods as a 
inner join rs_goods_multi as b 
    on a.goods_id = b.goods_id 
where b.goods_name LIKE 'sweater005%' 

看看這是否會給出更好的結果。