4.0 MyBatis_映射文件curd

- 日理万妓 2022-05-31 07:24 217阅读 0赞

第一步：在mysql数据库中建表

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第二步：使用eclipse创建项目

1.目录结构

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2.代码

Employee.java

package com.mybatis.bean;
    
    public class Employee {
    	private Integer id;
    	private String lastName;
    	private String email;
    	private String gender;
    	public Integer getId() {
    		return id;
    	}
    	public void setId(Integer id) {
    		this.id = id;
    	}
    	public String getLastName() {
    		return lastName;
    	}
    	public void setLastName(String lastName) {
    		this.lastName = lastName;
    	}
    	public String getEmail() {
    		return email;
    	}
    	public void setEmail(String email) {
    		this.email = email;
    	}
    	public String getGender() {
    		return gender;
    	}
    	public void setGender(String gender) {
    		this.gender = gender;
    	}
    	
    	public Employee(Integer id, String lastName, String email, String gender) {
    		super();
    		this.id = id;
    		this.lastName = lastName;
    		this.email = email;
    		this.gender = gender;
    	}
    	
    	
    	public Employee() {
    		super();
    		// TODO Auto-generated constructor stub
    	}
    	@Override
    	public String toString() {
    		return "Employee [id=" + id + ", lastName=" + lastName + ", email=" + email + ", gender=" + gender + "]";
    	}
    
    	
    
    }

映射文件EmployeeMapper.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">
      
     
     <mapper namespace="com.mybatis.dao.EmployeeMapper">
      
      <select id="getEmpbyID" resultType="com.mybatis.bean.Employee">
        select id,last_name lastName,email,gender from tbl_employee where id = #{id}
      </select>
      
      <update id="updateEmp" >
      	update tbl_employee set
        last_name = #{lastName},
        email = #{email},
        gender = #{gender}
      where id = #{id}
      </update>
      
      
      
    
      <insert id="addEmp" databaseId="mysql1" parameterType="com.mybatis.bean.Employee" useGeneratedKeys="true" keyProperty="id">
      	insert into tbl_employee(last_name,email,gender) values (#{lastName},#{email},#{gender})
      </insert>
      
     	
       
    	
    	<insert id="addEmp" databaseId="oracle1">	
    		<selectKey keyProperty="id" order="BEFORE" resultType="Integer">
      			
      			
      			select tbl_employee_sql.nextval from dual
      		</selectKey>
      		insert into tbl_employee(id,last_name,email,gender) values (#{tbl_employee_sql.nextval}#{lastName},#{email},#{gender})
      	</insert>
      	
     
      	
      <insert id="addEmp" databaseId="oracle1">
      	<selectKey keyProperty="id" order="AFTER" resultType="Integer">
      		
      		
      		select tbl_employee_sql.currentval from dual
      	</selectKey>
      	insert into tbl_employee(id,last_name,email,gender) values (#{tbl_employee_sql.currentval},#{lastName},#{email},#{gender})
      </insert>
      
      <delete id="deleteID" >
      	delete from tbl_employee where id=#{id}
      </delete>
    </mapper>

接口EmployeeMapper.java

package com.mybatis.dao;
    
    import com.mybatis.bean.Employee;
    
    public interface EmployeeMapper {
    	
    	public Employee getEmpbyID(Integer id);
    	
    	public void updateEmp(Employee employee);
    	
    	public void addEmp(Employee employee);
    
    	public int deleteID(Integer id);
    
    
    }

全局配置文件mybatis-config.xml

<?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>
    
    	
    	
    	<settings>  
            <setting name="logImpl" value="STDOUT_LOGGING"/>  
        </settings> 
        
      <environments default="mysql222">
        <environment id="mysql222">
          <transactionManager type="JDBC"/>
          <dataSource type="POOLED">
            <property name="driver" value="com.mysql.jdbc.Driver"/>
            <property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
            <property name="username" value="root"/>
            <property name="password" value="shapolang"/>
          </dataSource>
        </environment>
        
         <environment id="oracle222">
        	<transactionManager type="JDBC"></transactionManager>
        	<dataSource type="POOLED">
    			<property name="driver" value="${oracle.driver}"></property>
    			<property name="url" value="${oracle.url}"></property>
    			<property name="username" value="${oracle.username" ></property>
    			<property name="password" value="${oracle.password}"></property>
        	</dataSource>
        </environment>
     </environments>
       
      
      <databaseIdProvider type="DB_VENDOR">
      	<property name="MySQL" value="mysql1"/>
      	<property name="Oracle" value="oracle1"/>
      	<property name="SQL Server" value="sqlserver1"/>
      </databaseIdProvider>
      
      
      <mappers>
        <mapper resource="com/mybatis/bean/EmployeeMapper.xml"/>
      </mappers>
    </configuration>

测试类testMybatis.java

package test;
    
    import java.io.IOException;
    import java.io.InputStream;
    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;
    import org.junit.Test;
    import com.mybatis.bean.Employee;
    import com.mybatis.dao.EmployeeMapper;
    
    public class testMybatis{	
    	
    	private SqlSessionFactory getSqlSessionFactory() throws IOException {
    		String resource = "mybatis-config.xml";
    		InputStream inputStream = Resources.getResourceAsStream(resource);
    		SqlSessionFactory SqlSessionFactory =new SqlSessionFactoryBuilder().build(inputStream);
    		return SqlSessionFactory;
    	}
    
    
    	@Test
    	public void test1() throws IOException {
    		//1.获取SqlSessionFactory对象
    		SqlSessionFactory ssf= getSqlSessionFactory();
    		
    		//2.获取SqlSession对象
    		SqlSession ss=ssf.openSession();
    		
    		//3.获取接口的实现类对象
    		//会为接口自动创建一个代理对象，代理对象去执行增删改查方法
    		try {
    			  EmployeeMapper mapper = ss.getMapper(EmployeeMapper.class);
    			  Employee emp2 = mapper.getEmpbyID(2);
    			  System.out.println(emp2);
    			  System.out.println(mapper.getClass());//返回的是一个代理对象
    			} finally {
    			  ss.close();
    			}
    		
    	}
    	
    	/*
    	 * 测试增删改
    	 *	1.mybatis允许增删改直接定义以下类型返回值
    	 *		Interger、Long、Boolean、void
    	 *	2.我们需要手动提交数据
    	 *		sqlSessionFactory.openSession();--->手动提交
    	 *		sqlSessionFactory.openSession(true);--->自动提交
    	 */
    	@Test
    	public void test2() throws IOException {
    		SqlSessionFactory ssf=getSqlSessionFactory();
    		SqlSession ss=ssf.openSession();
    	
    		try{
    			EmployeeMapper mapper=ss.getMapper(EmployeeMapper.class);
    			//测试添加
    			Employee emp1=new Employee(null,"jeery","88@qq.com","1");	
    			mapper.addEmp(emp1);
    		//	System.out.println(emp1.getId());
    			
    			//测试更新
    		//	Employee emp1=new Employee(1,"tom","88@qq.com","1");
    		//	mapper.updateEmp(emp1);
    			
    			//测试删除
    		//	mapper.deleteID(6);
    			
    			//手动提交操作
    			ss.commit();
    		}finally {
    			ss.close();	
    		}	
    		
    	}
    	
    	//测试oracle从从序列中拿到的主键值
    	@Test
    	public void test3() throws IOException {
    		SqlSessionFactory ssf=getSqlSessionFactory();
    		SqlSession ss=ssf.openSession();
    		
    		try{
    			EmployeeMapper mapper=ss.getMapper(EmployeeMapper.class);
    	
    			Employee emp2=new Employee(null,"jack","88@qq.com","0");
    			mapper.addEmp(emp2);
    		
    			ss.commit();	
    		}finally {
    		ss.close();
    		}
    	}
    }

测试test3()打印结果：

==>  Preparing: insert into tbl_employee(last_name,email,gender) values (?,?,?) 
    ==> Parameters: jack(String), 88@qq.com(String), 0(String)
    <==    Updates: 1

[Center]: https://img-blog.csdn.net/20180211153119281?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQveWlndWFuZ184MjA=/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center
[Center 1]: /images/20220531/9e9b6f95e4e74cd5a908f3537e242759.png
[Center 2]: /images/20220531/31c3553760164d3f8a2e058720afb638.png