1.将A表中的一个或多个字段插入B表：
insert into tb_orgstruct(product_id,product_name,product_parent_id) SELECT DICTIONARIES_ID,NAME,PARENT_ID from sys_dictionaries
2.mybatis对表格某列求和：
<select id="findPrjNumInputByPoName" parameterType="page" resultType="Float">
select COALESCE(SUM(ACTUAL_INPUT),0) "prjNumInput" from
<include refid="tableName"></include>
where
PO = #{NW_PO_NAME}
</select>
原文：http://www.cnblogs.com/lingluo2017/p/6994491.html