Mybatis表关联一对多、多对一、多对多
项目工程结构如下：
1. 搭建MyBatis框架环境
首先需要引入两个包：mybatis.jar 和 sqljdbc42.jar包
若分页需要导入两个包：pagehelper-5.1.0.jar 和 jsqlparser-1.0.jar
设置 mybatis 配置文件：SqlMapConfig.xml, 在 src目录下建立此文件，内容如下：
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd"> <!-- 注意 <plugins> 在xml文件中的位置，必须要符合 http://mybatis.org/dtd/mybatis-3-config.dtd 中指定的顺序：-->
<!-- configuration (properties?, settings?, typeAliases?, typeHandlers?,
objectFactory?, objectWrapperFactory?, plugins?, environments?, databaseIdProvider?, mappers?) -->
<configuration>
<!-- 为SQL定义部分的parameterType或resultType属性指定自定义类型的别名 -->
<typeAliases>
<typeAlias alias="ServiceStation" type="com.mybatis.models.ServiceStation" />
<typeAlias alias="InspectorInfo" type="com.mybatis.models.InspectorInfo" />
<typeAlias alias="StationInspector" type="com.mybatis.models.StationInspector" />
</typeAliases>
<!-- 配置分页拦截器 -->
<plugins>
<!-- 配置分页插件 -->
<plugin interceptor="com.github.pagehelper.PageInterceptor"></plugin>
<!-- com.mybatis.util为PageHelper类所在包名 -->
<!-- <plugin interceptor="com.mybatis.util.PagePlugin"> -->
<!-- 设置数据库类型 Oracle,Mysql,MariaDB,SQLite,Hsqldb,PostgreSQL六种数据库-->
<!-- <property name="dialect" value="SQLite" /> -->
<!-- <property name="pageSqlId" value=".*Page.*" /> -->
<!-- </plugin> -->
</plugins>
<!-- 设置数据库连接参数 -->
<!-- 与spring 集成之后,这些可以完全删除,数据库连接的管理交给 spring 去管理 -->
<environments default="development">
<environment id="development">
<transactionManager type="JDBC" />
<dataSource type="POOLED">
<property name="driver" value="com.microsoft.sqlserver.jdbc.SQLServerDriver" />
<property name="url" value="jdbc:sqlserver://mssql-rw-cyp-coopbusiness.vip.test.suixinhuan.com;DatabaseName=CYP_CoopBusiness" />
<property name="username" value="Umanager" />
<property name="password" value="ASD123asd!1" />
</dataSource>
</environment>
</environments>
<!-- 加载SQL定义文件 -->
<!-- 这里交给sqlSessionFactory 的 mapperLocations属性去得到所有配置信息 -->
<mappers>
<mapper resource="com/mybatis/sql/ServiceStation.xml" />
<mapper resource="com/mybatis/sql/InspectorInfo.xml" />
<mapper resource="com/mybatis/sql/StationInspector.xml" />
</mappers>
</configuration>
2. 编写实体类
首先创建一个包：com.mybatis.models，并在其下创建与数据库表对应的三个实体类，分别如下：
ServiceStation.java 类
package com.mybatis.models; import java.util.Date;
import java.util.List; /**
* @author 自定义类
* 服务站类
*/
public class ServiceStation {
private String ID;
private String StationName;
private String CityCode;
private String CityName;
private String StationAddr;
private int IsEnabled;
private String Createor;
private String CreateorUser;
private Date CreateDate;
private List<StationInspector> StationInspectorList;
private List<InspectorInfo> InspectorInfoList; public String toString() {
return "服务站 [ ID = " + ID + ", StationName = " + StationName + ", "
+ "CityCode = " + CityCode + ", CityName = " + CityName + "]\n";
}
public String getID() {
return ID;
}
public void setID(String ID) {
this.ID = ID;
}
public String getStationName() {
return StationName;
}
public void setStationName(String StationName) {
this.StationName = StationName;
}
public String getCityCode() {
return CityCode;
}
public void setCityCode(String CityCode) {
this.CityCode = CityCode;
}
public String getCityName() {
return CityName;
}
public void setCityName(String CityName) {
this.CityName = CityName;
}
public String getStationAddr() {
return StationAddr;
}
public void setStationAddr(String StationAddr) {
this.StationAddr = StationAddr;
}
public int getIsEnabled() {
return IsEnabled;
}
public void setIsEnabled(int IsEnabled) {
this.IsEnabled = IsEnabled;
}
public String getCreateor() {
return Createor;
}
public void setCreateor(String Createor) {
this.Createor = Createor;
}
public String getCreateorUser() {
return CreateorUser;
}
public void setCreateorUser(String CreateorUser) {
this.CreateorUser = CreateorUser;
}
public Date getCreateDate() {
return CreateDate;
}
public void setCreateDate(Date CreateDate) {
this.CreateDate = CreateDate;
}
public List<StationInspector> getStationInspectorList() {
return StationInspectorList;
}
public void setStationInspectorList(List<StationInspector> StationInspectorList) {
this.StationInspectorList = StationInspectorList;
}
public List<InspectorInfo> getInspectorInfoList() {
return InspectorInfoList;
}
public void setInspectorInfoList(List<InspectorInfo> InspectorInfoList) {
this.InspectorInfoList = InspectorInfoList;
}
}
InspectorInfo.java 类
package com.mybatis.models; import java.util.Date;
import java.util.List; /**
* @author 自定义类
* 评估师类
*/
public class InspectorInfo {
private String ID;
private String CityCode;
private int InspectorID;
private String InspectorName;
private String InspectorUser;
private String Createor;
private String CreateorUser;
private Date CreateDate;
private List<ServiceStation> ServiceStationList; public String toString() {
return "评估师 [ CityCode = " + CityCode + ", InspectorID = " + InspectorID + ", "
+ "InspectorName = " + InspectorName + ", InspectorUser = " + InspectorUser + "]\n";
}
public String getID() {
return ID;
}
public void setID(String ID) {
this.ID = ID;
}
public String getCityCode() {
return CityCode;
}
public void setCityCode(String CityCode) {
this.CityCode = CityCode;
}
public int getInspectorID() {
return InspectorID;
}
public void setInspectorID(int InspectorID) {
this.InspectorID = InspectorID;
}
public String getInspectorName() {
return InspectorName;
}
public void setInspectorName(String InspectorName) {
this.InspectorName = InspectorName;
}
public String getInspectorUser() {
return InspectorUser;
}
public void setInspectorUser(String InspectorUser) {
this.InspectorUser = InspectorUser;
}
public String getCreateor() {
return Createor;
}
public void setCreateor(String Createor) {
this.Createor = Createor;
}
public String getCreateorUser() {
return CreateorUser;
}
public void setCreateorUser(String CreateorUser) {
this.CreateorUser = CreateorUser;
}
public Date getCreateDate() {
return CreateDate;
}
public void setCreateDate(Date CreateDate) {
this.CreateDate = CreateDate;
}
public List<ServiceStation> getServiceStationList() {
return ServiceStationList;
}
public void setServiceStationList(List<ServiceStation> ServiceStationList) {
this.ServiceStationList = ServiceStationList;
}
}
StationInspector.java 类
package com.mybatis.models; import java.util.Date; /**
* @author 自定义类
* 服务站与评估师关系类
*/
public class StationInspector {
private String ID;
private String StationID;
private int InspectorID;
private String Inspector;
private String InspectorUser;
private int InspectorRole;
private Date DateRule;
private String Createor;
private String CreateorUser;
private Date CreateDate;
private ServiceStation ServiceStation; public String toString() {
return "评估师 [ StationID = " + StationID + ", InspectorID = " + InspectorID + ", "
+ "Inspector = " + Inspector + ", InspectorUser = " + InspectorUser + "]\n";
}
public String getID() {
return ID;
}
public void setID(String ID) {
this.ID = ID;
}
public String getStationID() {
return StationID;
}
public void setStationID(String StationID) {
this.StationID = StationID;
}
public int getInspectorID() {
return InspectorID;
}
public void setInspectorID(int InspectorID) {
this.InspectorID = InspectorID;
}
public String getInspector() {
return Inspector;
}
public void setInspector(String Inspector) {
this.Inspector = Inspector;
}
public String getInspectorUser() {
return InspectorUser;
}
public void setInspectorUser(String InspectorUser) {
this.InspectorUser = InspectorUser;
}
public int getInspectorRole() {
return InspectorRole;
}
public void setInspectorRole(int InspectorRole) {
this.InspectorRole = InspectorRole;
}
public Date getDateRule() {
return DateRule;
}
public void setDateRule(Date DateRule) {
this.DateRule = DateRule;
}
public String getCreateor() {
return Createor;
}
public void setCreateor(String Createor) {
this.Createor = Createor;
}
public String getCreateorUser() {
return CreateorUser;
}
public void setCreateorUser(String CreateorUser) {
this.CreateorUser = CreateorUser;
}
public Date getCreateDate() {
return CreateDate;
}
public void setCreateDate(Date CreateDate) {
this.CreateDate = CreateDate;
}
public ServiceStation getServiceStation() {
return ServiceStation;
}
public void setServiceStation(ServiceStation ServiceStation) {
this.ServiceStation = ServiceStation;
}
}
3. 编写SQL定义文件（映射文件）
首先创建一个包：com.mybatis.sql，并在其下创建与这三个实体类对应的映射文，详细如下代码所示：
ServiceStation.java 类对应的映射文件 ServiceStation.xml
<?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"> <!-- namespace指定和哪个接口映射 -->
<mapper namespace="com.mybatis.dao.ServiceStationMapper">
<!-- resultType是select特有 -->
<select id="findAll" resultType="com.mybatis.models.ServiceStation">
select * from T_TRA_ServiceStation
</select> <select id="findAllPage" resultType="ServiceStation" parameterType="String">
select * from T_TRA_ServiceStation where CityCode=#{CityCode}
</select> <select id="findById" resultType="ServiceStation" parameterType="String">
select * from T_TRA_ServiceStation where ID=#{ID}
</select> <insert id="save" parameterType="ServiceStation">
insert into T_TRA_ServiceStation values (#{ID},#{StationName},#{CityCode},#{CityName})
</insert> <update id="update" parameterType="com.mybatis.models.ServiceStation">
update T_TRA_ServiceStation set Createor=#{Createor},CreateorUser=#{CreateorUser} where ID=#{ID}
</update> <!-- 如果parameterType为单个值，#{标识符}表达式标识符没有约定 -->
<delete id="delete" parameterType="String">
delete from T_TRA_ServiceStation where ID=#{ID}
</delete> <!-- Mybatis表关联多对多查询 方法配置 -->
<resultMap type="ServiceStation" id="resultServiceStationMap">
<result property="StationName" column="StationName" />
<result property="CityCode" column="CityCode" />
<result property="CityName" column="CityName" />
<collection property="InspectorInfoList"
select="com.mybatis.dao.StationInspectorMapper.getInspectorInfoListByStationID"
column="ID" />
</resultMap>
<select id="selectServiceStation" resultMap="resultServiceStationMap" parameterType="String">
select * from T_TRA_ServiceStation where DeleteTag = AND CityCode='' AND ID=#{ID}
</select> </mapper>
InspectorInfo.java 类对应的映射文件 InspectorInfo.xml
<?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"> <!-- namespace指定和哪个接口映射 -->
<mapper namespace="com.mybatis.dao.InspectorInfoMapper">
<!-- resultType是select特有 -->
<select id="findAll" resultType="com.mybatis.models.InspectorInfo">
select * from T_TRA_InspectorInfo
</select> <select id="findById" resultType="InspectorInfo" parameterType="String">
select * from T_TRA_InspectorInfo where ID=#{ID}
</select> <parameterMap type="com.mybatis.models.InspectorInfo" id="parameterInspectorInfoMap">
<parameter property="ID"/>
<parameter property="CityCode"/>
<parameter property="InspectorID"/>
<parameter property="InspectorName"/>
</parameterMap>
<insert id="save" parameterMap="parameterInspectorInfoMap">
insert into T_TRA_InspectorInfo values (#{ID},#{CityCode},#{InspectorID},#{InspectorName})
</insert> <!-- Mybatis表关联多对多查询 方法配置 -->
<resultMap type="InspectorInfo" id="resultInspectorInfoMap">
<result property="CityCode" column="CityCode" />
<result property="InspectorID" column="InspectorID" />
<collection property="ServiceStationList"
select="com.mybatis.dao.StationInspectorMapper.getServiceStationListByInspectorID"
column="InspectorID" />
</resultMap>
<select id="selectInspectorInfo" resultMap="resultInspectorInfoMap" parameterType="int">
select * from T_TRA_InspectorInfo WHERE DeleteTag = AND CityCode = '' AND InspectorID=#{InspectorID}
</select> </mapper>
StationInspector.java 类对应的映射文件 StationInspector.xml
<?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"> <!-- namespace指定和哪个接口映射 -->
<mapper namespace="com.mybatis.dao.StationInspectorMapper">
<!-- Mybatis表关联一对多查询 方法配置 -->
<resultMap type="ServiceStation" id="resultServiceStationMap">
<id property="ID" column="ID" />
<result property="ID" column="ServiceStation_ID" /> <!-- 注意这列起了别名 -->
<result property="StationName" column="StationName" />
<result property="CityCode" column="CityCode" />
<result property="CityName" column="CityName" />
<!-- 方法1 多表链接查询方式 -->
<!-- <collection property="StationInspectorList" ofType="com.mybatis.models.StationInspector">
<id property="ID" column="ID" javaType="string" jdbcType="VARCHAR" />
<result property="StationID" column="StationID" />
<result property="InspectorID" column="InspectorID" javaType="int" jdbcType="INTEGER" />
<result property="Inspector" column="Inspector" javaType="string" jdbcType="VARCHAR" />
<result property="InspectorUser" column="InspectorUser" />
<result property="InspectorRole" column="InspectorRole" />
</collection> -->
<!-- 方法2 多表单独查询方式 -->
<collection property="StationInspectorList" ofType="com.mybatis.models.StationInspector"
select="findStationInspector"
column="ID" />
</resultMap> <!-- 注意：两张表中的主键id字段名要唯一，例如不能都写id，不然的话，在一对多查询的时候就会出现只有一条记录 -->
<!-- <select id="selectServiceStation" resultMap="resultServiceStationMap" parameterType="String">
SELECT SS.ID AS ServiceStation_ID,SS.StationName,SS.CityCode,SS.CityName,SI.StationID,SI.InspectorID,SI.Inspector,SI.InspectorUser,SI.InspectorRole
FROM T_TRA_ServiceStation AS SS WITH (NOLOCK)
LEFT JOIN T_TRA_StationInspector AS SI WITH (NOLOCK) ON SS.ID=SI.StationID AND SI.DeleteTag= AND SI.DateRule='2018-08-01'
WHERE SS.CityCode='' AND SS.ID=#{ID}
ORDER BY SI.InspectorID
</select> --> <!-- 方法2 多表单独查询方式 -->
<select id="findStationInspector" resultType="com.mybatis.models.StationInspector">
select * from T_TRA_StationInspector where StationID=#{ID} AND DeleteTag= AND DateRule='2018-08-01'
</select>
<select id="selectServiceStation2" resultMap="resultServiceStationMap">
select * from T_TRA_ServiceStation where CityCode='' AND ID=#{ID}
</select> <!-- Mybatis表关联多对一查询 方法配置 -->
<resultMap type="com.mybatis.models.StationInspector" id="resultStationInspectorMap">
<id property="ID" column="ID" />
<result property="StationID" column="StationID" />
<result property="InspectorID" column="InspectorID" />
<result property="Inspector" column="Inspector" />
<result property="InspectorUser" column="InspectorUser" />
<result property="InspectorRole" column="InspectorRole" />
<!-- 方法1 多表链接查询方式 -->
<!-- <association property="ServiceStation" javaType="com.mybatis.models.ServiceStation">
<id property="ID" column="ID" />
<result property="ID" column="ServiceStation_ID" />
<result property="StationName" column="StationName" />
<result property="CityCode" column="CityCode" />
<result property="CityName" column="CityName" />
</association> -->
<!-- 方法2 多表单独查询方式 -->
<association property="ServiceStation" javaType="com.mybatis.models.ServiceStation"
select="findServiceStation"
column="StationID" />
</resultMap> <!-- 注意：两张表中的主键id字段名要唯一，例如不能都写id，不然的话，在一对多查询的时候就会出现只有一条记录 -->
<!-- <select id="selectStationInspector" resultMap="resultStationInspectorMap" parameterType="int">
SELECT SS.ID AS ServiceStation_ID,SS.StationName,SS.CityCode,SS.CityName,SI.StationID,SI.InspectorID,SI.Inspector,SI.InspectorUser,SI.InspectorRole
FROM T_TRA_StationInspector AS SI WITH (NOLOCK)
INNER JOIN T_TRA_ServiceStation AS SS WITH (NOLOCK) ON SS.ID=SI.StationID AND SS.CityCode=''
WHERE SI.DeleteTag= AND SI.DateRule='2018-08-01' AND SI.InspectorID=#{InspectorID}
ORDER BY SI.InspectorID
</select> --> <!-- 方法2 多表单独查询方式 -->
<select id="findServiceStation" resultType="com.mybatis.models.ServiceStation">
select * from T_TRA_ServiceStation where ID=#{ID} AND CityCode=''
</select>
<select id="selectStationInspector2" resultMap="resultStationInspectorMap">
select * from T_TRA_StationInspector where DeleteTag= AND DateRule='2018-08-01' AND InspectorID = #{InspectorID}
</select> <!-- Mybatis表关联多对多查询 方法配置 -->
<!-- 根据一个服务站ID,查看这个服务站下的所有的评估师 -->
<resultMap type="InspectorInfo" id="resultInspectorInfoMap_2">
<result property="CityCode" column="CityCode" />
<result property="InspectorID" column="InspectorID" />
<result property="InspectorName" column="InspectorName" />
</resultMap> <select id="getInspectorInfoListByStationID" resultMap="resultInspectorInfoMap_2" parameterType="String">
SELECT II.*, SI.StationID
FROM T_TRA_InspectorInfo II, T_TRA_StationInspector SI
WHERE II.InspectorID=SI.InspectorID AND SI.StationID=#{ID} AND SI.DeleteTag= AND SI.DateRule='2018-08-01'
</select> <!-- 根据一个评估师ID,查看这个评估师所对应的所有服务站-->
<resultMap type="ServiceStation" id="resultServiceStationMap_2">
<result property="StationName" column="StationName" />
<result property="CityCode" column="CityCode" />
<result property="CityName" column="CityName" />
</resultMap> <select id="getServiceStationListByInspectorID" resultMap="resultServiceStationMap_2" parameterType="int">
SELECT SS.*, SI.InspectorID
FROM T_TRA_ServiceStation SS, T_TRA_StationInspector SI
WHERE SS.ID=SI.StationID AND SI.InspectorID=#{InspectorID} AND SI.DeleteTag= AND SI.DateRule in ('2018-06-01','2018-08-01','2018-09-01')
</select>
</mapper>
说明：SQL参数部分，可以使用${标识符}或#{标识符}，如果使用#{}内部采用预编译机制执行SQL操作。如果使用${}内部采用非预编译过程。
下面是对这几个配置文件一点解释说明：
1、配置文件 SqlMapConfig.xml 是 mybatis 用来建立 sessionFactory，里面主要包含了数据库连接相关内容，还有 java 类所对应的别名，比如：<typeAlias alias="ServiceStation" type="com.mybatis.models.ServiceStation" /> 这个别名非常重要，在具体的类的映射中，比如：ServiceStation.xml 中 resultType 或 parameterType 就是对应这个。要保持一致，这里的 resultType 还有另外单独的定义方式，后面学习到我们再详细介绍说明。
2、SqlMapConfig.xml 里面 的 <mapper resource="com/mybatis/sql/ServiceStation.xml" /> 是包含要映射的类的 xml 配置文件。
3、在ServiceStation.xml 文件里面主要是定义各种 SQL 语句，以及这些语句的参数，以及要返回的类型等等。
4. 编写Mapper接口(Mapper映射器)
首先创建一个包：com.mybatis.dao，并在其下创建三个接口，分别如下：
ServiceStationMapper.java 类：
package com.mybatis.dao; import java.util.List; import org.apache.ibatis.annotations.Param; import com.mybatis.models.ServiceStation;
import com.mybatis.util.Page; /**
* 编写Mapper接口(Mapper映射器)
* 方法定义参考SQL定义的id、parameterType、resultType属性
* 1.方法名与id属性一致
* 2.参数类型与parameterType属性一致
* 3.返回结果：多行查询List<resultType>；单行查询 resultType；增删改为void或int
* 4.SQL定义文件中namespace="com.mybatis.dao.ServiceStationMapper"
*/
public interface ServiceStationMapper {
public List<ServiceStation> findAll(); public List<ServiceStation> findAllPage(@Param("CityCode") String CityCode); public List<ServiceStation> findAllPage(@Param("page") Page page, @Param("CityCode") String CityCode); public ServiceStation findById(String id); public int save(ServiceStation obj); public int update(ServiceStation obj); public int delete(String id); /*
* 给多对多查询用
*/
public ServiceStation selectServiceStation(String StationID);
}
InspectorInfoMapper.java 类：
package com.mybatis.dao; import com.mybatis.models.InspectorInfo; /**
* 编写Mapper接口(Mapper映射器)
* 方法定义参考SQL定义的id、parameterType、resultType属性
* 1.方法名与id属性一致
* 2.参数类型与parameterType属性一致
* 3.返回结果：多行查询List<resultType>；单行查询 resultType；增删改为void或int
* 4.SQL定义文件中namespace="com.mybatis.dao.InspectorInfoMapper"
*/
public interface InspectorInfoMapper {
/*
* 给多对多查询用
*/
public InspectorInfo selectInspectorInfo(int InspectorID);
}
StationInspectorMapper.java 类：
package com.mybatis.dao; import com.mybatis.models.ServiceStation;
import com.mybatis.models.StationInspector; /**
* 编写Mapper接口(Mapper映射器)
* 方法定义参考SQL定义的id、parameterType、resultType属性
* 1.方法名与id属性一致
* 2.参数类型与parameterType属性一致
* 3.返回结果：多行查询List<resultType>；单行查询 resultType；增删改为void或int
* 4.SQL定义文件中namespace="com.mybatis.dao.StationInspectorMapper"
*/
public interface StationInspectorMapper {
/*
* 给一对多查询用
*/
public ServiceStation selectServiceStation(String StationID); /*
* 给一对多查询用
*/
public ServiceStation selectServiceStation2(String StationID); /*
* 给多对一查询用
*/
public StationInspector selectStationInspector(int InspectorID); /*
* 给多对一查询用
*/
public StationInspector selectStationInspector2(int InspectorID);
}
5. 获取SqlSession操作
package com.mybatis.dao; import java.io.IOException;
import java.io.Reader; import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder; /*
* 获取SqlSession操作（公共方法）
*/
public class MyBatisUtil {
public static SqlSession getSession() {
SqlSessionFactoryBuilder builder = new SqlSessionFactoryBuilder();
Reader reader;
try {
reader = Resources.getResourceAsReader("SqlMapConfig.xml");
SqlSessionFactory factory = builder.build(reader);
SqlSession session = factory.openSession();
return session;
} catch (IOException e) {
// TODO 自动生成的 catch 块
e.printStackTrace();
return null;
}
}
}
6. 利用SqlSession获取Mapper接口对象
运行程序测试结果，在 src 目录下建立一个包：com.mybatis，并在其下创建一个类：HelloMyBatisProgram, 来运行测试配置环境是否成功，具体代码如下示：
package com.mybatis; import java.util.List; import org.apache.ibatis.session.SqlSession; import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.mybatis.dao.InspectorInfoMapper;
import com.mybatis.dao.MyBatisUtil;
import com.mybatis.dao.ServiceStationMapper;
import com.mybatis.dao.StationInspectorMapper;
import com.mybatis.models.ServiceStation;
import com.mybatis.models.InspectorInfo;
import com.mybatis.models.StationInspector;
//import com.mybatis.util.Page; /*
* 测试类
*/
public class HelloMyBatisProgram {
public static void main(String[] args) {
SqlSession session = MyBatisUtil.getSession();
//由框架生成ServiceStationMapper接口实现对象
ServiceStationMapper ssDaoMaper = session.getMapper(ServiceStationMapper.class);
InspectorInfoMapper iiDaoMaper = session.getMapper(InspectorInfoMapper.class);
StationInspectorMapper siDaoMaper = session.getMapper(StationInspectorMapper.class);
//System.out.println(ssDaoMaper.getClass().getName());
System.out.println("===========分页获取所有服务站列表============");
//Page page = new Page();
//page.setShowCount(3);
//page.setCurrentPage(1);
//List<ServiceStation> listPage = ssDaoMaper.findAllPage(page, "110100");
//System.out.println("分页查找总数：" + page.getTotalCount()); //分页设置放在查询之前
Page<Object> page = PageHelper.startPage(, , "StationName");
List<ServiceStation> listPage = ssDaoMaper.findAllPage("");
for(ServiceStation item:listPage) {
System.out.println(item.getStationName()+" "+item.getCityCode()+" "+item.getCityName());
}
System.out.println("当前页码："+page.getPageNum());
System.out.println("每页的记录数："+page.getPageSize());
System.out.println("总记录数："+page.getTotal());
System.out.println("总页码："+page.getPages());
System.out.println("===========获取所有服务站列表============");
//分页设置放在查询之前
page = PageHelper.startPage(, , "StationName desc");
List<ServiceStation> list = ssDaoMaper.findAll();
for(ServiceStation item:list) {
System.out.println(item.getStationName()+" "+item.getCityCode()+" "+item.getCityName());
}
PageInfo<ServiceStation> info = new PageInfo<ServiceStation>(list, );
System.out.println("当前页码："+info.getPageNum());
System.out.println("每页的记录数："+info.getPageSize());
System.out.println("总记录数："+info.getTotal());
System.out.println("总页码："+info.getPages());
System.out.println("是否第一页："+info.isIsFirstPage());
System.out.println("连续显示的页码：");
int[] nums = info.getNavigatepageNums();
for (int i = ; i < nums.length; i++) {
System.out.println(nums[i]);
}
System.out.println("===========多表关联【一对多】查询 ============");
ServiceStation objServiceStation = siDaoMaper.selectServiceStation2("");
System.out.println(objServiceStation);
List<StationInspector> list1 = objServiceStation.getStationInspectorList();
System.out.println(list1.size());
System.out.println(list1);
System.out.println("===========多表关联【多对一】查询 ============");
StationInspector objStationInspector = siDaoMaper.selectStationInspector2();
System.out.println(objStationInspector);
System.out.println(objStationInspector.getServiceStation());
System.out.println("===========多表关联【多对多】查询 ============");
InspectorInfo objInspectorInfo = iiDaoMaper.selectInspectorInfo();
System.out.println(objInspectorInfo);
List<ServiceStation> list2 = objInspectorInfo.getServiceStationList();
System.out.println(list2.size());
System.out.println(list2);
System.out.println("===========");
ServiceStation objServiceStation2 = ssDaoMaper.selectServiceStation("");
System.out.println(objServiceStation2);
List<InspectorInfo> list3 = objServiceStation2.getInspectorInfoList();
System.out.println(list3.size());
System.out.println(list3);
System.out.println("===========查找单个服务站信息============");
ServiceStation findObj = ssDaoMaper.findById("");
System.out.println(findObj.getStationName()+" "+findObj.getCityCode()+" "+findObj.getCityName());
System.out.println("===========更新单个服务站信息============");
ServiceStation updateObj = ssDaoMaper.findById("");
updateObj.setCreateor("周锐北京");
updateObj.setCreateorUser("zhouruibj");
// 执行更新
int result = ssDaoMaper.update(updateObj);
// 提交事务(注意：增删改之后必须执行提交)
session.commit();
System.out.println("更新返回结果：" + result);
session.close();
}
}
运行测试后部分截图如下：
Mybatis表关联一对多、多对一、多对多的更多相关文章
- Mybatis表关联一对多
有了前面几章的基础,对一些简单的应用是可以处理的,但在实际项目中,经常是关联表的查询,比如:最常见到的多对一,一对多等.这些查询是如何处理的呢,这一讲就讲这个问题.前面几篇教程中介绍的都是单表映射的一 ...
- 后盾网lavarel视频项目---lavarel多表关联一对多操作实例
后盾网lavarel视频项目---lavarel多表关联一对多操作实例 一.总结 一句话总结: 1.一对多中多那个部分的数据前端通过json弄到服务器 2.所有通过一操作多的时候,都要用上模型中定义的 ...
- Mybatis表关联多对一
在上章的 一对多 中,我们已经学习如何在 Mybatis 中关联多表,但在实际项目中也是经常使用 多对一 的情况,这些查询是如何处理的呢,在这一节中我们来学习它.多表映射的多对一关系要用到 mybit ...
- mybatis表关联彻底理解
1.多张表关联 三张表,用户表,主播表,关注表. 查询用户已经关注的主播的信息,那就要三张表关联起来啊.分别left join联在一起,通过id相同的连接在一起.最后where查找出最终条件. < ...
- Mybatis表关联多对多
创建表 创建表对应的 JavaBean 对象 package com.tanlei.newer.model; import java.util.List; /** * @author:Mr.Tan * ...
- JDBC上关于数据库中多表操作一对多关系和多对多关系的实现方法
黑马程序员 我们知道,在设计一个Javabean的时候,要把这些BEAN 的数据存放在数据库中的表结构,然而这些数据库中的表直接又有些特殊的关系,例如员工与部门直接有一对多的关系,学生与老师直接又多对 ...
- 20.Yii2.0框架多表关联一对多查询之hasMany
目录 新手模式 hasMany关联模式查询 新建mode层Article.php 新建mode层Category.php 新建控制器HomeController.php 新手模式 用上次的查询结果,作 ...
- 21.Yii2.0框架多表关联一对多查询之性能优化--模型的使用
控制器里 功能: 通过分类,查分类下的所有文章 //关联查询 public function actionRelatesearch(){ //关联查询 //查询方法一(查一行) 一维数组下的值是obj ...
- Mybatis 一对一、一对多、多对多关联之级联添加
示例项目:MIPO_CRM 一.一对一关联 示例:订单与销售机会 描述:在业务员与客户的联系人的联系记录中可以生成一条销售机会,而此条销售机会可生成一条订单,两者呈一对一关联. 1.表设计 oppor ...
随机推荐
- vue中router-link的详细用法
官网文档地址:https://router.vuejs.org/zh/api/#to 今天项目突然有需求,让vue中的一个页面跳转到另一个页面 // 字符串 <router-link to=&q ...
- 从输入URL到浏览页面的过程
之前我们已经讨论过浏览器的渲染原理,今天我们来讨论下更广泛的从输入URL到渲染出页面的过程. 1. 查询该URL是否有缓存 如果有,则直接返回,没有的话,下一步 2. 查询URL对应的IP 首先,到 ...
- 配置Notepad++
Notepad++配置 1.自动换行 视图 - 自动换行 2.隐藏工具栏 设置 - 首选项... > 常用 > 工具栏 - 隐藏 3.隐藏菜单栏 设置 - 首选项... > 常用 & ...
- linux下redis的安装、启动、关闭和卸载
edis 在Linux 和 在Windows 下的安装是有很大的不同的,和通常的软件安装是一样的． 一 下载 Redis 安装包 去redis 官网下载reids 安装包, redis 官网默认只提 ...
- WebSocket浅谈
WebSocket是HTML5开始提供的一种在单个 TCP 连接上进行全双工通讯的协议. 在WebSocket API中,浏览器和服务器只需要做一个握手的动作,然后,浏览器和服务器之间就形成了一条快速 ...
- Codeforces Round #596 (Div. 2, based on Technocup 2020 Elimination Round 2)
A - Forgetting Things 题意:给 \(a,b\) 两个数字的开头数字(1~9),求使得等式 \(a=b-1\) 成立的一组 \(a,b\) ,无解输出-1. 题解:很显然只有 \( ...
- postgresql数据的入门教程
postgreSQL数据库简介 PostgreSQL 是一个免费的对象-关系数据库服务器(ORDBMS),在灵活的BSD许可证下发行. PostgreSQL 开发者把它念作 post-gress-Q- ...
- Python3 输入和输出（一）
1.输出格式美化 Python两种输出值的方式: 表达式语句和 print() 函数. 第三种方式是使用文件对象的 write() 方法,标准输出文件可以用 sys.stdout 引用. 如果希望输出 ...
- arcgis python 新生成的数据设置
try: # Update the spatial index(es) # r = arcpy.CalculateDefaultGridIndex_management(outFeatures) ar ...
- 【Java】 HashMap
Java HashMap 标签(空格分隔): Java source-code hash-map 总结 HashTable的基本数据结构 Entry的hash与table的长度计算indexFor才能 ...