背景:
有一张评议人表(e_evaluator),一张参评企业表(attend_enterprise_info),一张评议人和参评企业关系表(er_evaluator_attend_enterprise),关系如下图
目前e_evaluator表中有3800条数据,attend_enterprise_info表中有130条数据,er_evaluator_attend_enterprise表中有42000条数据
通过中间表er_evaluator_attend_enterprise,建立一个e_evaluator与多个e_attend_enterprise的一对多关系
java代码调用
long s1 = System.currentTimeMillis(); // 所有评议人 List<Evaluator> evaluatorLst = this.evaluatorMapper.queryEvaluators(evaluatorParam); long s2 = System.currentTimeMillis(); log.info("用时:" + (s2 - s1))
mybatis的xml文件用到了两种写法
第一种写法:
第一步:配置返回的resultMap
<resultMap id="BaseResultMap" type="com.hhsoft.evaluation.model.dto.Evaluator" > <id column="evaluator_id" property="evaluatorId" jdbcType="VARCHAR" /> <result column="evaluator_name" property="evaluatorName" jdbcType="VARCHAR" /> <result column="account" property="account" jdbcType="VARCHAR" /> <result column="password" property="password" jdbcType="VARCHAR" /> <result column="login_status" property="loginStatus" jdbcType="VARCHAR" /> <result column="gender" property="gender" jdbcType="VARCHAR" /> <result column="mobile" property="mobile" jdbcType="VARCHAR" /> <result column="administrative_area_code" property="administrativeAreaCode" jdbcType="VARCHAR" /> <result column="administrative_area_name" property="administrativeAreaName" jdbcType="VARCHAR" /> <result column="administrative_area_grade" property="administrativeAreaGrade" jdbcType="VARCHAR" /> <result column="questionnaire_id" property="questionnaireId" jdbcType="VARCHAR" /> <result column="evaluator_type" property="evaluatorType" jdbcType="VARCHAR" /> <result column="city_code" property="cityCode" jdbcType="VARCHAR" /> <result column="city_name" property="cityName" jdbcType="VARCHAR" /> <result column="county_code" property="countyCode" jdbcType="VARCHAR" /> <result column="county_name" property="countyName" jdbcType="VARCHAR" /> <result column="position_name" property="positionName" jdbcType="VARCHAR" /> <result column="organization_name" property="organizationName" jdbcType="VARCHAR" /> <result column="create_user_id" property="createUserId" jdbcType="VARCHAR" /> <result column="create_time" property="createTime" jdbcType="TIMESTAMP" /> <result column="update_user_id" property="updateUserId" jdbcType="VARCHAR" /> <result column="update_time" property="updateTime" jdbcType="TIMESTAMP" /> <result column="order_no" property="orderNo" jdbcType="FLOAT" /> <result column="status" property="status" jdbcType="INTEGER" /> <result column="office_people_id" property="officePeopleId" jdbcType="VARCHAR" /> <result column="work_unit" property="workUnit" jdbcType="VARCHAR" /> <result column="office_id" property="officeId" jdbcType="VARCHAR" /> <result column="answer_status" property="answerStatus" jdbcType="INTEGER" /> <collection property="attendEnterpriseLst" ofType="com.hhsoft.evaluation.model.dto.AttendEnterprise" > <id column="attend_enterprise_id" property="attendEnterpriseId"/> <result column="attend_enterprise_name" property="attendEnterpriseName"/> </collection> </resultMap>
其中,重点在collection
<collection property="attendEnterpriseLst" ofType="com.hhsoft.evaluation.model.dto.AttendEnterprise" > <id column="attend_enterprise_id" property="attendEnterpriseId"/> <result column="attend_enterprise_name" property="attendEnterpriseName"/> </collection>
查询的sql
<select id="queryEvaluators" resultMap="BaseResultMap" parameterType="com.hhsoft.evaluation.model.dto.Evaluator" > SELECT eei.evaluator_id, eei.evaluator_name, eei.account, eei.password, eei.login_status, eei.gender, eei.mobile, eei.administrative_area_code, eei.administrative_area_grade, eei.questionnaire_id, eei.evaluator_type, eei.city_code, eei.county_code, eei.position_name, eei.organization_name, eei.create_user_id, eei.create_time, eei.update_user_id, eei.update_time, eei.order_no, eei.status, eei.office_people_id, eei.work_unit, eei.office_id, b1.area_name administrative_area_name, b2.area_name city_name, b3.area_name county_name, eeae.attend_enterprise_id, eae.attend_enterprise_name FROM e_evaluator eei LEFT JOIN b_area b1 ON b1.area_code = eei.administrative_area_code LEFT JOIN b_area b2 ON b2.area_code = eei.city_code LEFT JOIN b_area b3 ON b3.area_code = eei.county_code LEFT JOIN e_office_info eoi ON eoi.office_id = eei.office_id LEFT JOIN e_office_people_info eopi ON eopi.office_people_id = eei.office_people_id LEFT JOIN er_evaluator_attend_enterprise eeae ON eei.evaluator_id = eeae.evaluator_id LEFT JOIN e_attend_enterprise eae ON eeae.attend_enterprise_id = eae.attend_enterprise_id where eei.status = 0 and eeae.status = 0 ORDER BY eei.city_code, eei.county_code, eoi.order_no,eopi.order_no, eei.order_no <!-- 分页 --> <include refid="pagerB"></include> </select>
用时:10463ms
第二种写法:
第一步:配置返回的resultMap
<resultMap id="BaseResultMap" type="com.hhsoft.evaluation.model.dto.Evaluator" > <id column="evaluator_id" property="evaluatorId" jdbcType="VARCHAR" /> <result column="evaluator_name" property="evaluatorName" jdbcType="VARCHAR" /> <result column="account" property="account" jdbcType="VARCHAR" /> <result column="password" property="password" jdbcType="VARCHAR" /> <result column="login_status" property="loginStatus" jdbcType="VARCHAR" /> <result column="gender" property="gender" jdbcType="VARCHAR" /> <result column="mobile" property="mobile" jdbcType="VARCHAR" /> <result column="administrative_area_code" property="administrativeAreaCode" jdbcType="VARCHAR" /> <result column="administrative_area_name" property="administrativeAreaName" jdbcType="VARCHAR" /> <result column="administrative_area_grade" property="administrativeAreaGrade" jdbcType="VARCHAR" /> <result column="questionnaire_id" property="questionnaireId" jdbcType="VARCHAR" /> <result column="evaluator_type" property="evaluatorType" jdbcType="VARCHAR" /> <result column="city_code" property="cityCode" jdbcType="VARCHAR" /> <result column="city_name" property="cityName" jdbcType="VARCHAR" /> <result column="county_code" property="countyCode" jdbcType="VARCHAR" /> <result column="county_name" property="countyName" jdbcType="VARCHAR" /> <result column="position_name" property="positionName" jdbcType="VARCHAR" /> <result column="organization_name" property="organizationName" jdbcType="VARCHAR" /> <result column="create_user_id" property="createUserId" jdbcType="VARCHAR" /> <result column="create_time" property="createTime" jdbcType="TIMESTAMP" /> <result column="update_user_id" property="updateUserId" jdbcType="VARCHAR" /> <result column="update_time" property="updateTime" jdbcType="TIMESTAMP" /> <result column="order_no" property="orderNo" jdbcType="FLOAT" /> <result column="status" property="status" jdbcType="INTEGER" /> <result column="office_people_id" property="officePeopleId" jdbcType="VARCHAR" /> <result column="work_unit" property="workUnit" jdbcType="VARCHAR" /> <result column="office_id" property="officeId" jdbcType="VARCHAR" /> <result column="answer_status" property="answerStatus" jdbcType="INTEGER" /> <collection property="attendEnterpriseLst" select="queryErAttendEnterpriseEvaluator" column="evaluator_id"> </collection> </resultMap>
重点还是在collection
<collection property="attendEnterpriseLst" select="queryErAttendEnterpriseEvaluator" column="evaluator_id"> </collection>
sql语句
<select id="queryEvaluators" resultMap="BaseResultMap" parameterType="com.hhsoft.evaluation.model.dto.Evaluator" > SELECT eei.evaluator_id, eei.evaluator_name, eei.account, eei.password, eei.login_status, eei.gender, eei.mobile, eei.administrative_area_code, eei.administrative_area_grade, eei.questionnaire_id, eei.evaluator_type, eei.city_code, eei.county_code, eei.position_name, eei.organization_name, eei.create_user_id, eei.create_time, eei.update_user_id, eei.update_time, eei.order_no, eei.status, eei.office_people_id, eei.work_unit, eei.office_id, b1.area_name administrative_area_name, b2.area_name city_name, b3.area_name county_name FROM e_evaluator eei LEFT JOIN b_area b1 ON b1.area_code = eei.administrative_area_code LEFT JOIN b_area b2 ON b2.area_code = eei.city_code LEFT JOIN b_area b3 ON b3.area_code = eei.county_code LEFT JOIN e_office_info eoi ON eoi.office_id = eei.office_id LEFT JOIN e_office_people_info eopi ON eopi.office_people_id = eei.office_people_id where eei.status = 0 ORDER BY eei.city_code, eei.county_code, eoi.order_no,eopi.order_no, eei.order_no <!-- 分页 --> <include refid="pagerB"></include> </select>
关联关系select用到的sql语句
<select id="queryErAttendEnterpriseEvaluator" parameterType="string" resultType="com.hhsoft.evaluation.model.dto.AttendEnterprise"> select eae.attend_enterprise_id attendEnterpriseId, eae.attend_enterprise_name attendEnterpriseName from e_attend_enterprise eae left join er_evaluator_attend_enterprise eeae on eeae.attend_enterprise_id = eae.attend_enterprise_id where eeae.evaluator_id = #{evaluator_id} </select>
用时:4862ms
效率提高一倍。具体原理待分析