如下使用 + 号，字符串拼接，将只可以查找到一行
SELECT * FROM pur_order A right JOIN pur_supplier B ON LOCATE(','+B.id+',', ','+A.supplier_ids+',')>0 where B.id =3
正确的写法应该如下：
SELECT * FROM pur_order A
right join pur_email B on LOCATE(concat(',',B.id,','),concat( ',',A.supplier_ids,','))>0
WHERE B.ID = 3
