1、创建xml目录
在src/main/resources/目录下新建mybatis文件夹，将xxx.xml文件放入该文件夹内（也可以创建多级目录）
2、在application.yml文件中配置：
mybatis:
configuration:
mapUnderscoreToCamelCase: true
mapperLocations: mybatis/*Mapper.xml
3、在Dao接口文件中加注解@Mapper，注意使用xml文件写sql语句要将接口方法上的sql语句去掉
@Mapper
public interface MrInfoMapper
{
/**
* 根据条件查询MR信息
* @param param
* @return
*/
public List<Map<String, Object>> findByCondition(Map<String, Object> param);
/**
* 获取页面展示数据
* @param param
* @return
*/
// @Select("<script>" + "SELECT" + " group_concat(id) id," + " max(mi.mr) mr," + " mi.intf_file,"
// + " max(mi.area) area," + " max(mi.rversion) rversion," + " concat("
// + " ifnull(case when mi.ce='Y' then 'CE ' end,''),"
// + " ifnull(case when mi.ne='Y' then 'NE ' end,''),"
// + " ifnull(case when mi.ptn='Y' then 'PTN ' end,''),"
// + " ifnull(case when mi.rtn='Y' then 'RTN ' end,''),"
// + " ifnull(case when mi.trans='Y' then 'TRANS ' end,'')" + ") products,"
// + " group_concat(distinct mi.change_type) change_type," + " max(mi.table_flag) table_flag" + " FROM "
// + " tb_mr_info mi " + "WHERE" + " mi.intf_file IS NOT NULL" + " AND mi.table_flag = #{searchDate} "
// + "<if test=\"productList != null \">" + "<foreach item=\"item\" collection=\"productList\" >"
// + " and ${item}='Y'" + "</foreach>" + "</if>" + "GROUP BY" + " mi.intf_file" + "</script>")
public List<HashMap<String, String>> findDisplayData(Map<String, Object> param);
4、在xxxmapper.xml文件中写SQL，注意namesapce值不要写错。
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.huawei.nos.nosimsys.dao.MrInfoMapper">
<select id="findByCondition" parameterType="map" resultType="map">
SELECT
*
FROM
tb_mr_info tmi
WHERE 1=1
AND tmi.table_flag=#{searchDate}
<if test="productList != null and productList != ''">
<foreach collection="productList" item="item">
and ${item}='Y'
</foreach>
</if>
</select>