mysql - 慢查询如何优化

Question

mysql慢查询语句该如何优化

SELECT * FROM `x_order` LEFT JOIN x_goods ON x_goods.goods_id = x_order.order_goodsid WHERE `order_isdelete` = 0 AND `goods_type` = 0 GROUP BY order_no

Answer 1

Build an index
order_isdelete goods_type order_no goods_id
Consider how to build an index to optimize the query for these fields.

Answer 2

Where group by select, try to do it on the index

Answer 3

1. Try not to use JOIN and migrate functions from SQL to code level processing

2. Index