CREATE TABLE `temp` (
`page_id` bigint(20) DEFAULT NULL,
`section_id` bigint(20) DEFAULT NULL,
`visit_category_id` bigint(20) DEFAULT NULL,
`cart_category_id` bigint(20) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
数据表category结构
-- Table "category" DDL
CREATE TABLE `category` (
`category_id` bigint(20) DEFAULT NULL,
`category_name` varchar(128) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
关联temp表和category表，取出visit_category_id和cart_category_id对应的category_name
select a.page_id,
a.section_id,
a.visit_category_id,
b.category_name,
a.cart_category_id,
c.category_name
from temp a
left outer join category b on (a.visit_category_id=b.category_id)
left outer join category c on (a.cart_category_id=c.category_id);
