场景：category_ids 值为1,2,4
查询 category_ids = 2 和 4的所有记录
查询语句：
$map['category_id']=array('in',$category_ids)❌

$category_ids =1,2,3

$map[] =['category_id','in',$category_ids]; ✔

根据字段查表名(用于检索全库带有该字段的表)

精确查询

SELECT * FROM information_schema.columns WHERE column_name='column_name'; //column_name为字段名

ALTER TABLE ecs_order_upfile add test VARCHAR(64) DEFAULT NULL COMMENT '测试'