MyBatis--学习第二天

<?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">
<configuration>
    <!--引入properties 属性配置文件 使用相对路径方式-->
    <properties resource="jdbc.properties"></properties>
    <!--设置日志的处理方式 默认 是log4j 也可以写出来-->
    <settings>
        <setting name="logImpl" value="LOG4J"/>
    </settings>
    <!--扫描实体类包 给所有实体类自动生成别名  生成的别名就是 类名首字母小写-->
    <typeAliases>
        <package name="com.bjsxt.entity"></package>
    </typeAliases>
    <!--environment 代表mybatis框的配置信息-->
    <environments default="mysql"> <!--指定默认使用哪个连接信息 如果指定的不存在 那么就使用第一个-->
        <environment id="mysql"><!--可以配置mysql连接信息-->
            <transactionManager type="JDBC"/><!--事务管理器-->
            <dataSource type="POOLED"><!--以连接池形式管理连接对象 连接池配置信息-->
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>

    </environments>
    <mappers>
       <!-- <mapper class="com.bjsxt.mapper.EmpMapper"></mapper>-->
        <package name="com.bjsxt.mapper"></package>
    </mappers>
</configuration>

import com.bjsxt.entity.Emp;
import org.apache.ibatis.annotations.Param;

import java.util.List;

public interface EmpMapper {
    List<Emp> finAll();

    /**
     * 根据编号查询
     *
     * @param empno 要查找的员工编号
     * @return 根据员工查到的信息封装到Emp对象
     */
    Emp getEmpByEmpno(int empno);

    /**
     * @param empno 查询的员工编号
     * @param ename 查询的员工姓名
     * @return 根据员工姓名和编号返回的员工对象
     */
    Emp getEmpByEmpnoAndEname(int empno, String ename);

    /**
     * @param empno
     * @param ename
     * @return
     */
    Emp getEmpByEmpnoAndEname2(@Param("a") int empno, @Param("b") String ename);


    /**
     * @param emp
     * @return
     */
    Emp getEmpByEmpnoAndEname3(Emp emp);

    /**
     * @param empa
     * @param empb
     * @return
     */
    Emp getEmpByEmpnoAndEname4(@Param("a") Emp empa, @Param("b") Emp empb);
}

<?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">
<!--注意
这里放入的namespace从今天 开始不能随便写 必须是接口名
接口名和 mapper映射 文件名必须相同
-->
<mapper namespace="com.bjsxt.mapper.EmpMapper">
    <select id="finAll" resultType="emp">
        select * from emp
    </select>

    <select id="getEmpByEmpno" resultType="emp">
        select * from emp where empno=#{empno}
    </select>

    <select id="getEmpByEmpnoAndEname" resultType="emp">
        select * from emp where empno=#{0} and ename=#{1}
    </select>

    <select id="getEmpByEmpnoAndEname2" resultType="emp">
        select * from emp where empno=#{a} and ename=#{b}
    </select>

    <select id="getEmpByEmpnoAndEname3" resultType="emp">
         select * from emp where empno=#{empno} and ename=#{ename}
    </select>

    <select id="getEmpByEmpnoAndEname4" resultType="emp" parameterType="emp">
        select * from emp where empno=#{a.empno} and ename=#{b.ename}
    </select>
</mapper>

package com.bjsxt.entity;

import java.util.Date;

/*
    对应数据库实体类的要求
    1所有属性必须是私有化的
    2每个属性必须有get和set方法
    3必须存在空参数构造方法
     */
public class Emp {
    private int empno;
    private String ename;
    private String job;
    private int mgr;
    private Date hiredate;
    private double sal;
    private double comm;
    private int deptno;

    public Emp() {
    }

    public Emp(int empno, String ename, String job, int mgr, Date hiredate, double sal, double comm, int deptno) {
        this.empno = empno;
        this.ename = ename;
        this.job = job;
        this.mgr = mgr;
        this.hiredate = hiredate;
        this.sal = sal;
        this.comm = comm;
        this.deptno = deptno;
    }

    public int getEmpno() {
        return empno;
    }

    public void setEmpno(int empno) {
        this.empno = empno;
    }

    public String getEname() {
        return ename;
    }

    public void setEname(String ename) {
        this.ename = ename;
    }

    public String getJob() {
        return job;
    }

    public void setJob(String job) {
        this.job = job;
    }

    public int getMgr() {
        return mgr;
    }

    public void setMgr(int mgr) {
        this.mgr = mgr;
    }

    public Date getHiredate() {
        return hiredate;
    }

    public void setHiredate(Date hiredate) {
        this.hiredate = hiredate;
    }

    public double getSal() {
        return sal;
    }

    public void setSal(double sal) {
        this.sal = sal;
    }

    public double getComm() {
        return comm;
    }

    public void setComm(double comm) {
        this.comm = comm;
    }

    public int getDeptno() {
        return deptno;
    }

    public void setDeptno(int deptno) {
        this.deptno = deptno;
    }

    @Override
    public String toString() {
        return "Emp{" +
                "empno=" + empno +
                ", ename='" + ename + '\'' +
                ", job='" + job + '\'' +
                ", mgr=" + mgr +
                ", hiredate=" + hiredate +
                ", sal=" + sal +
                ", comm=" + comm +
                ", deptno=" + deptno +
                '}';
    }
}

package com.bjsxt.test;

import com.bjsxt.entity.Emp;
import com.bjsxt.mapper.EmpMapper;
import org.apache.ibatis.session.SqlSession;

import java.util.List;

public class Test {
    public static void main(String[] args) {
        SqlSession sqlSession = TestUtils.getSqlSession();
        EmpMapper mapper = sqlSession.getMapper(EmpMapper.class);
        List<Emp> emps = mapper.finAll();
        for (Emp e : emps
        ) {
            System.out.println(e);
        }
        System.out.println("---------------------------------------");
        Emp empno = mapper.getEmpByEmpno(7566);
        System.out.println(empno);

        System.out.println("---------------------------------------");
        Emp martin = mapper.getEmpByEmpnoAndEname(7654, "MARTIN");
        System.out.println(mapper);

        System.out.println("---------------------------------------");
        Emp ename = mapper.getEmpByEmpnoAndEname(7654, "MARTIN");
        System.out.println(ename);

        System.out.println("---------------------------------------");
        Emp emp=new Emp();
        emp.setEmpno(7844);
        emp.setEname("TURNER");
        Emp ename3 = mapper.getEmpByEmpnoAndEname3(emp);
        System.out.println(ename3);

        System.out.println("---------------------------------------");
        Emp empa=new Emp();
        empa.setEmpno(7900);
        Emp empb=new Emp();
        empb.setEname("JAMES");
        Emp ename4 = mapper.getEmpByEmpnoAndEname4(empa, empb);
        System.out.println(ename4);

        sqlSession.close();
    }
}

package com.bjsxt.mapper;
import com.bjsxt.entity.Emp;
import java.util.List;
public interface EmpMapper {
    List<Emp> findAll();
    Emp getEmpByEmpno(int empno);
}

<mapper namespace="com.bjsxt.mapper.EmpMapper">
    <!--id属性必须是接口中的方法名-->
    <select id="findAll" resultType="emp">
        SELECT * from emp
    </select>
    <!--单个基础数据类型参数 #中相当于形参列表的参数名
    可以随便写 但是尽量和接口中的形参 名保持一致-->
    <select id="getEmpByEmpno" resultType="emp">
        SELECT *  FROM   emp where empno =#{empno}
    </select>
</mapper>

import com.bjsxt.entity.Emp;
import java.util.List;
public interface EmpMapper {
    List<Emp> findAll();
    Emp getEmpByEmpno(int empno);
    Emp getEmpByEmpnoAndEname(int empno,String ename);
}

<?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">
<!--注意
这里放入的namespace从今天 开始不能随便写 必须是接口名
接口名和 mapper映射 文件名必须相同
-->
<mapper namespace="com.bjsxt.mapper.EmpMapper">
    <!--id属性必须是接口中的方法名-->
    <select id="findAll" resultType="emp">
        SELECT * from emp
    </select>
    <!--单个基础数据类型参数 #中相当于形参列表的参数名
    可以随便写 但是尽量和接口中的形参 名保持一致-->
    <select id="getEmpByEmpno" resultType="emp">
        SELECT *  FROM   emp where empno =#{empno}
    </select>
    <!--
    多个基础数据类型参数 mybatis会将参数放入一个数组
    #中放的是参数列表中参数的索引
    索引从0开始
    -->
    <select id="getEmpByEmpnoAndEname" resultType="emp">
        <!--select * FROM   emp where empno = #{0} and ename= #{1}-->
        select * FROM   emp where empno = #{param1} and ename= #{param2}
    </select>
</mapper>

EmpMapper mapper = sqlSession.getMapper(EmpMapper.class);
        Emp emp = mapper.getEmpByEmpnoAndEname(7566,"JONES");
        System.out.println(emp);
        sqlSession.close();

package com.bjsxt.mapper;
import com.bjsxt.entity.Emp;
import org.apache.ibatis.annotations.Param;
import java.util.List;
public interface EmpMapper {
    List<Emp> findAll();
    Emp getEmpByEmpno(int empno);
    Emp getEmpByEmpnoAndEname(int empno,String ename);
    Emp getEmpByEmpnoAndEname2(@Param("a") int empno,@Param("b") String ename);
}

<select id="getEmpByEmpnoAndEname2" resultType="emp">
        
        select * FROM   emp where empno = #{a} and ename= #{b}
    </select>

 EmpMapper mapper = sqlSession.getMapper(EmpMapper.class);
        Emp emp = mapper.getEmpByEmpnoAndEname2(7566,"JONES");
        System.out.println(emp);
        sqlSession.close();

import com.bjsxt.entity.Emp;
import org.apache.ibatis.annotations.Param;
import java.util.List;
public interface EmpMapper {
    List<Emp> findAll();
    Emp getEmpByEmpno(int empno);
    Emp getEmpByEmpnoAndEname(int empno,String ename);
    Emp getEmpByEmpnoAndEname2(@Param("a") int empno,@Param("b") String ename);
    Emp getEmpByEmpnoAndEname3(Emp emp);
}

 <!--parameterType="emp" 可以不写  单个引用类型 # 中直接写属性名-->
    <select id="getEmpByEmpnoAndEname3" resultType="emp" parameterType="emp">
       select * FROM   emp where empno = #{empno} and ename= #{ename}
    </select>

EmpMapper mapper = sqlSession.getMapper(EmpMapper.class);
        Emp emp =new Emp();
        emp.setEmpno(7566);
        emp.setEname("JONES");
        Emp res = mapper.getEmpByEmpnoAndEname3(emp);
        System.out.println(res);
        sqlSession.close();

import com.bjsxt.entity.Emp;
import org.apache.ibatis.annotations.Param;
import java.util.List;
public interface EmpMapper {
    List<Emp> findAll();
    Emp getEmpByEmpno(int empno);
    Emp getEmpByEmpnoAndEname(int empno,String ename);
    Emp getEmpByEmpnoAndEname2(@Param("a") int empno,@Param("b") String ename);
    Emp getEmpByEmpnoAndEname3(Emp emp);
    Emp getEmpByEmpnoAndEname4(@Param("a") Emp empa,@Param("b") Emp empb);
}

 <!--parameterType="emp" 可以不写 多个引用类型
    # 中使用param*.对象属性名
    或者使用 别名.属性名
    -->
    <select id="getEmpByEmpnoAndEname4" resultType="emp" parameterType="emp" >
        select * FROM   emp where empno = #{param1.empno} and ename= #{param2.ename}
        <!-- select * FROM   emp where empno = #{a.empno} and ename= #{b.ename} -->
    </select>

EmpMapper mapper = sqlSession.getMapper(EmpMapper.class);
        Emp empa =new Emp();
        empa.setEmpno(7566);
        Emp empb =new Emp();
        empb.setEmpno(7566);
        empb.setEname("JONES");
        Emp res = mapper.getEmpByEmpnoAndEname4(empa,empb);
        System.out.println(res);
        sqlSession.close();

public interface EmpMapperX {
    int deleteEmpByEmpno(int empno);
    int updateEmpByEmpno(Emp emp);
    int addEmp(Emp emp);
}

<?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">
<!--注意
这里放入的namespace从今天 开始不能随便写 必须是接口名
接口名和 mapper映射 文件名必须相同
-->
<mapper namespace="com.bjsxt.mapper.EmpMapperX">
    <insert id="addEmp">
         insert into emp values (default,#{ename},#{job},#{mgr},#{hiredate},#{sal},#{comm},#{deptno})
    </insert>
    <update id="updateEmpByEmpno" parameterType="emp">
        update emp set
        ename =#{ename},
        job=#{job},
        mgr=#{mgr},
        hiredate=#{hiredate},
        sal=#{sal},
        comm=#{comm},
        deptno=#{deptno}
        where empno=#{empno}
    </update>
    <delete id="deleteEmpByEmpno" parameterType="emp">
         delete from emp where empno =#{empno}
    </delete>
</mapper>

public class TestX {
    public static void main(String[] args) {
        SqlSession sqlSession = TestUtil.getSqlSession();
        EmpMapperX ex=sqlSession.getMapper(EmpMapperX.class);
      /*  int i = ex.deleteEmpByEmpno(7369);
        System.out.println(i);*/
        /*Emp emp =new Emp();
        emp.setEmpno(7521);
        emp.setEname("XiaoMing");
        emp.setMgr(7839);
        emp.setJob("SALESMAN");
        emp.setHiredate(new Date());
        emp.setSal(2000);
        emp.setComm(200);
        emp.setDeptno(30);
        int i = ex.updateEmpByEmpno(emp);*/
        Emp emp =new Emp();
        emp.setEname("XiaoHong");
        emp.setMgr(7839);
        emp.setJob("SALESMAN");
        emp.setHiredate(new Date());
        emp.setSal(3000);
        emp.setComm(100);
        emp.setDeptno(10);
        int i = ex.addEmp(emp);
        System.out.println(i);
        sqlSession.commit();
        sqlSession.close();
    }

public interface EmpMapper2 {
    List<Emp> getEmpByConditionx(int empno,String ename);
    List<Emp> getEmpByCondition1(Emp emp);
    List<Emp> getEmpByCondition2(Emp emp);
    List<Emp> getEmpByCondition3(Emp emp);
}

<?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.bjsxt.mapper.EmpMapper2">
    <!--测试if语句  如果只有一个参数必须使用别名处理 但是一个参数还用动态sql么?-->
    <select id="getEmpByConditionx"  resultType="emp" >
        select  * from emp where 1=1
        <if test="param1 != 0">
            and empno =  #{param1}
        </if>
        <if test="param2 != null and param2 !=  ''">
            and ename =  #{param2}
        </if>
    </select>
    <!--测试if语句-->
    <select id="getEmpByCondition1"  resultType="emp" parameterType="emp">
        select * from emp WHERE 1=1
        <if test="empno != 0 ">
            and  empno =#{empno}
        </if>
        <if test="ename != null and  ename !='' ">
            and  ename =#{ename}
        </if>
        <if test="job != null and  job !='' ">
            and  job =#{job}
        </if>
        <if test="mgr != 0  ">
            and  mgr =#{mgr}
        </if>
        <if test="sal != 0    ">
            and  sal =#{sal}
        </if>
        <if test="comm != 0    ">
            and  comm = #{comm}
        </if>
        <if test="deptno != 0    ">
            and  deptno =#{deptno}
        </if>
    </select>
    <!--测试whereif-->
    <select id="getEmpByCondition2"  resultType="emp" parameterType="emp">
        select * from emp
        <where>
            <if test="empno != 0 ">
                and  empno =#{empno}
            </if>
            <if test="ename != null and  ename !='' ">
                and  ename =#{ename}
            </if>
            <if test="job != null and  job !='' ">
                and  job =#{job}
            </if>
            <if test="mgr != 0  ">
                and  mgr =#{mgr}
            </if>
            <if test="hiredate != null">
                                                                                                                                        hiredate = #{hiredate}
                                                                                                    </if>
            <if test="sal != 0    ">
                and  sal =#{sal}
            </if>
            <if test="comm != 0    ">
                and  comm = #{comm}
            </if>
            <if test="deptno != 0    ">
                and  deptno =#{deptno}
            </if>
        </where>
    </select>
    <!--测试whereif-->
    <select id="getEmpByCondition3"  resultType="emp" parameterType="emp">
        select * from emp
        <where>
            <choose>
                <when test="empno != 0 ">
                    and  empno =#{empno}
                </when>
                <when test="ename != null and  ename !='' ">
                    and  ename =#{ename}
                </when>
                <when test="job != null and  job !='' ">
                    and  job =#{job}
                </when>
                <when test="mgr != 0  ">
                    and  mgr =#{mgr}
                </when>
               <when test="hiredate != null">
                                                                                                                                        hiredate = #{hiredate}
                                                                                                     </when>
                <when test="sal != 0    ">
                    and  sal =#{sal}
                </when>
                <when test="comm != 0    ">
                    and  comm = #{comm}
                </when>
                <when test="deptno != 0    ">
                    and  deptno =#{deptno}
                </when>
                <otherwise>
                    1=1
                </otherwise>
            </choose>
        </where>
    </select>
</mapper>

public class Test2 {
    public static void main(String[] args) {
        SqlSession sqlSession = TestUtil.getSqlSession();
        EmpMapper2 mapper = sqlSession.getMapper(EmpMapper2.class);
        Emp emp =new Emp();
        /*emp.setEname("XiaoMing");
        emp.setJob("SALESMAN");*/
       /* emp.setMgr(7839);*/
       /*emp.setDeptno(20);*/
       /*emp.setHiredate(new java.sql.Date(119,8,3));*/
        List<Emp> emps = mapper.findEmpByCondition(emp);
        for (Emp e:emps
             ) {
            System.out.println(e);
        }
    }

public interface EmpMapper3 {
    int updateEmpByEmpno(Emp emp);
    int updateEmpByEmpno2(Emp emp);
}

<?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.bjsxt.mapper.EmpMapper3">
    <update id="updateEmpByEmpno" parameterType="emp">
        update emp
        <!-- set 只能用于修改语句
        自动处理 set关键字和 逗号 问题-->
        <set>
            <if test="ename != null and ename != ''">
                ename =#{ename},
            </if>
            <if test="job != null and ename != ''">
                job =#{job},
            </if>
            <if test="sal !=0 ">
                sal =#{sal},
            </if>
            <if test="mgr !=0 ">
                mgr =#{mgr},
            </if>
            <if test="comm !=0 ">
                comm =#{comm},
            </if>
            <if test="deptno !=0 ">
                deptno =#{deptno},
            </if>
            <if test="hiredate != null ">
                hiredate =#{hiredate},
            </if>
        </set>
        where empno =#{empno}
    </update>
    <!--
        prefix:增加前缀
        prefixOverrides：去除前缀
        suffix：增加后缀
        suffixOverrides：去除后缀
        trim 比set功能更强大
        set可以看做 是 set的一种特殊情况
    -->
    <update id="updateEmpByEmpno2" parameterType="emp">
        update emp
        <trim prefix="set"  suffixOverrides=",">
            <if test="ename != null and ename != ''">
                ename =#{ename},
            </if>
            <if test="job != null and ename != ''">
                job =#{job},
            </if>
            <if test="sal != 0 ">
                sal =#{sal},
            </if>
            <if test="mgr != 0 ">
                mgr =#{mgr},
            </if>
            <if test="comm != 0 ">
                comm =#{comm},
            </if>
            <if test="deptno !=0 ">
                deptno =#{deptno},
            </if>
            <if test="hiredate != null ">
                hiredate =#{hiredate},
            </if>
        </trim>
        where empno =#{empno}
    </update>
</mapper>

 public static void main(String[] args) {
        SqlSession sqlSession = TestUtil.getSqlSession();
        EmpMapper3 m = sqlSession.getMapper(EmpMapper3.class);
        Emp emp =new Emp();
        emp.setEmpno(7566);
        emp.setEname("SUN");
        emp.setComm(1000);
        emp.setDeptno(30);
        emp.setJob("CLERK");
        System.out.println(new java.sql.Date(119,5,8));
        emp.setHiredate(date);
        int i = m.updateEmpByEmpno2(emp);
        System.out.println(i);
        sqlSession.commit();
        sqlSession.close();
    }

 public List<Emp> getEmpsByDeptnos(List<Integer> deptnos);
    public List<Emp> getEmpsByDeptnos2(int  ... deptnos);
    /*因为参数只有一个映射文件中使用 param1 或者使用@Param 定义别名*/
    List<Emp> getEmpsByEnameLike(@Param("ename") String  ename);

<?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.bjsxt.mapper.EmpMapper4">
    <sql id="baseEmpSelect">
        select empno,ename,job,mgr,hiredate,sal,comm,deptno from emp
    </sql>
    <!--查看API文档 看foreach集合和数组作为方法参数时候的处理
    map.put("list",数组或者集合)
    -->
    <select id="getEmpsByDeptnos" resultType="emp">
        <include refid="baseEmpSelect"/> where deptno IN
        <foreach collection="list" item="deptno" open="(" close=")" separator=",">
            #{deptno}
        </foreach>
    </select>
    <select id="getEmpsByDeptnos2" resultType="emp">
        <include refid="baseEmpSelect"/> where deptno IN
        <foreach collection="array" item="deptno" open="(" close=")" separator=",">
            #{deptno}
        </foreach>
    </select>
    <!--参数只有一个 可以使用param1 或者在接口上的别名-->
    <select id="getEmpsByEnameLike"  resultType="emp">
        <bind name="likePattern" value="'%'+param1+'%'"></bind>
        <include refid="baseEmpSelect"/>
        where ename like #{likePattern}
    </select>
</mapper>

public static void main(String[] args) {
        SqlSession sqlSession = TestUtil.getSqlSession();
        EmpMapper4 m = sqlSession.getMapper(EmpMapper4.class);
        /*List<Integer> deptnos  =new LinkedList<Integer>();
        deptnos.add(10);
        deptnos.add(20);
        List<Emp> emps = m.getEmpsByDeptnos(deptnos);*/
        int[] deptnos ={10,20};
        List<Emp> emps = m.getEmpsByDeptnos2(deptnos);
        for (Emp emp:emps
             ) {
            System.out.println(emp);
        }
        emps = m.getEmpsByEnameLike("s");
        for (Emp emp:emps
                ) {
            System.out.println(emp);
        }
        sqlSession.close();
    }

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

public class TestUtils {
    public static SqlSession getSqlSession() {
        SqlSession sqlSession = null;
        try {
            InputStream is = Resources.getResourceAsStream("mybatis.xml");
            SqlSessionFactoryBuilder factoryBuilder = new SqlSessionFactoryBuilder();
            SqlSessionFactory sqlSessionFactory = factoryBuilder.build(is);
            sqlSession = sqlSessionFactory.openSession();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return sqlSession;
    }
}