MyBatis多表关联查询

来源：互联网发布：网络电影比较大尺度的编辑：程序博客网时间：2024/05/17 22:27

1：最简单粗暴的笨办法就是自定义一个智能的实体类，把多表查询需要的字段列出属性，注意实体类的属性名和数据库字段名保持一致

2：两个表一对多关联

实体类

public class BasicInfo{    private Integer basicInfoId;    private Integer projectId;//项目ID    private String keyNo;//公司内部关联主键    private String name;//企业名称    private String no;//注册号    private String belongOrg;//登记机关    private String operName;//法定代表人    private String startDate;//成立日期    private String endDate;//注销/吊销日期    private String status;//登记状态（存续、在业、注销、迁入、吊销、迁出、停业、清算）    private String province;//所在省份缩写    private String updateDate;//更新日期    private String creditCode;//统一社会信用代码    private String registCapi;//注册资本    private String econKind;//类型    private String address;//住所    private String scope;//经营范围    private String termStart;//营业期限自    private String teamEnd;//营业期限至    private String checkDate;//核准日期    private String sysTime;//        private List<ChangeRecords> changeRecordsList;  //变更记录     .....

public class ChangeRecords {    private Integer changeRecordsId;    private Integer basicInfoId;    private String projectName;    private String beforeContent;    private String afterContent;    private String changeDate;    public Integer getChangeRecordsId() {        return changeRecordsId;    }    public void setChangeRecordsId(Integer changeRecordsId) {        this.changeRecordsId = changeRecordsId;    }        public String getProjectName() {        return projectName;    }    public void setProjectName(String projectName) {        this.projectName = projectName;    }    public String getBeforeContent() {        return beforeContent;    }    public void setBeforeContent(String beforeContent) {        this.beforeContent = beforeContent;    }    public String getAfterContent() {        return afterContent;    }    public void setAfterContent(String afterContent) {        this.afterContent = afterContent;    }    public String getChangeDate() {        return changeDate;    }    public void setChangeDate(String changeDate) {        this.changeDate = changeDate;    }public Integer getBasicInfoId() {return basicInfoId;}public void setBasicInfoId(Integer basicInfoId) {this.basicInfoId = basicInfoId;}    }

xml文件

<resultMap id="BaseResultMap" type="com.cybernaut.core.model.BasicInfo" >    <id column="basic_info_id" property="basicInfoId" jdbcType="INTEGER" />    <result column="project_id" property="projectId" jdbcType="INTEGER" />    <result column="key_no" property="keyNo" jdbcType="VARCHAR" />    <result column="name" property="name" jdbcType="VARCHAR" />    <result column="no" property="no" jdbcType="VARCHAR" />    <result column="belong_org" property="belongOrg" jdbcType="VARCHAR" />    <result column="oper_name" property="operName" jdbcType="VARCHAR" />    <result column="start_date" property="startDate" jdbcType="VARCHAR" />    <result column="end_date" property="endDate" jdbcType="VARCHAR" />    <result column="status" property="status" jdbcType="VARCHAR" />    <result column="province" property="province" jdbcType="VARCHAR" />    <result column="update_date" property="updateDate" jdbcType="VARCHAR" />    <result column="credit_code" property="creditCode" jdbcType="VARCHAR" />    <result column="regist_capi" property="registCapi" jdbcType="VARCHAR" />    <result column="econ_kind" property="econKind" jdbcType="VARCHAR" />    <result column="address" property="address" jdbcType="VARCHAR" />    <result column="scope" property="scope" jdbcType="VARCHAR" />    <result column="term_start" property="termStart" jdbcType="VARCHAR" />    <result column="team_end" property="teamEnd" jdbcType="VARCHAR" />    <result column="check_date" property="checkDate" jdbcType="VARCHAR" />    <result column="sys_time" property="sysTime" jdbcType="VARCHAR" />    <!-- 变更记录 -->    <collection property="changeRecordsList" ofType="com.cybernaut.core.model.ChangeRecords" column="basic_info_id"           select="change_records.selectByChangeRecordsId"></collection></resultMap><sql id="Base_Column_List" >    basic_info_id, project_id, key_no, name, no, belong_org, oper_name, start_date, end_date,     status, province, update_date, credit_code, regist_capi, econ_kind, address, scope,     term_start, team_end, check_date, sys_time</sql>

3：一对一

basic实体类里面的list改成单个对象

xml文件里<collection...>改成

<association property="对象名称" javaType="

com.cybernaut.core.model.ChangeRecords

" column="basic_info_id" select="change_records.selectSupervisor"/>

另外一种方式

<association property="对象名称" javaType="

com.cybernaut.core.model.ChangeRecords"

resultMap="changeRecordsResultMap"/></resultMap><resultMap id="changeRecordsResultMap" type="com.cybernaut.core.model.ChangeRecords"><id property="id" column="t_id"/><result property="name" column="t_name"/><result property="gender" column="t_gender"/><result property="researchArea" column="t_research_area"/><result property="title" column="t_title"/></resultMap>

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