mysql同一个表中两条数据进行合并
<!--获取公司和主营产品信息-->
<select id="selectUserExt" resultMap="getUserExt">
select u.user_id,u.user_name,u.company_name,u.are_name,u.address,u.web,u.tel,u.fax,u.u_describe,
GROUP_CONCAT(m.mainproduct_name) AS mainproduct_name
FROM `user` u
INNER JOIN mainproduct m
on user_id=m.company_id
AND user_id=#{userId,jdbcType=INTEGER}
</select>
<!--获取联系人信息-->
<select id="selectPeopleExt" resultMap="getUserExt">
select CONCAT(c.principal_name,' ', b.business_department_name,' ',c.mphone) as principal_name
FROM contactinfo c,business_department b
WHERE c.business_department_id=b.business_department_id
AND company_id=#{userId,jdbcType=INTEGER}
UNION
select CONCAT(c.principal_name, ' ',b.business_department_name,' ',c.mphone) as principal_name
FROM contactinfo c,business_department b
WHERE c.business_department_id=b.business_department_id
AND company_id=#{userId,jdbcType=INTEGER}
</select>