MyBatis注解之动态SQL实战

ゝ一纸荒年。 2021-07-24 13:37 619阅读 0赞

**一  领域模型**

package org.fkit.domain;
    import java.io.Serializable;
    /**
    *
    CREATE TABLE tb_employee (
      ID INT(11) PRIMARY KEY AUTO_INCREMENT,
      loginname VARCHAR(18),
      PASSWORD VARCHAR(18),
      NAME VARCHAR(18) DEFAULT NULL,
      SEX CHAR(2) DEFAULT NULL,
      AGE INT(11) DEFAULT NULL,
      phone VARCHAR(21),
      sal DOUBLE,
      state VARCHAR(18)
    )
    INSERT INTO  tb_employee(loginname,PASSWORD,NAME,sex,age,phone,sal,state)
    VALUES('jack','123456','杰克','男',26,'13902019999',9800,'ACTIVE');
      INSERT INTO  tb_employee(loginname,PASSWORD,NAME,sex,age,phone,sal,state)
    VALUES('rose','123456','露丝','女',21,'13902018888',6800,'ACTIVE');
    * */
    public class Employee implements Serializable {
         
         private static final long serialVersionUID = 1L;
         
         private Integer id;              // 主键id
         private String loginname;   // 登录名
         private String password;    // 密码
         private String name;        // 真实姓名
         private String sex;              // 性别
         private Integer age;        // 年龄
         private String phone;       // 电话
         private Double sal;             // 薪水
         private String state;      // 状态
         
         public Employee() {
               super();
               // TODO Auto-generated constructor stub
         }
         public Integer getId() {
               return id;
         }
         public void setId(Integer id) {
               this.id = id;
         }
         public String getLoginname() {
               return loginname;
         }
         public void setLoginname(String loginname) {
               this.loginname = loginname;
         }
         public String getPassword() {
               return password;
         }
         public void setPassword(String password) {
               this.password = password;
         }
         public String getName() {
               return name;
         }
         public void setName(String name) {
               this.name = name;
         }
         public String getSex() {
               return sex;
         }
         public void setSex(String sex) {
               this.sex = sex;
         }
         public Integer getAge() {
               return age;
         }
         public void setAge(Integer age) {
               this.age = age;
         }
         public String getPhone() {
               return phone;
         }
         public void setPhone(String phone) {
               this.phone = phone;
         }
         public Double getSal() {
               return sal;
         }
         public void setSal(Double sal) {
               this.sal = sal;
         }
         public String getState() {
               return state;
         }
         public void setState(String state) {
               this.state = state;
         }
         @Override
         public String toString() {
               return "Employee [id=" + id + ", loginname=" +  loginname
                         + ", password=" + password + ", name=" +  name + ", sex=" + sex
                         + ", age=" + age + ", phone=" + phone + ",  sal=" + sal
                         + ", state=" + state + "]";
         }
    }

**二 会话工厂**

package org.fkit.factory;
    
    import java.io.InputStream;
    
    import org.apache.ibatis.io.Resources;
    import org.apache.ibatis.session.SqlSession;
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.apache.ibatis.session.SqlSessionFactoryBuilder;
    
    public class FKSqlSessionFactory {
        
        private static SqlSessionFactory sqlSessionFactory = null;
        
        // 初始化创建SqlSessionFactory对象
        static{
            try (// 读取mybatis-config.xml文件
                    InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
                ){
                sqlSessionFactory = new SqlSessionFactoryBuilder()
                        .build(is);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        
        // 获取SqlSession对象的静态方法
        public static SqlSession getSqlSession(){
            return sqlSessionFactory.openSession();
        }
    
        // 获取SqlSessionFactory的静态方法
        public static SqlSessionFactory getSqlSessionFactory() {
            return sqlSessionFactory;
        }
    
    }

**三 mapper**

1 EmployeeMapper

package org.fkit.mapper;
    
    import java.util.List;
    import java.util.Map;
    import org.apache.ibatis.annotations.DeleteProvider;
    import org.apache.ibatis.annotations.InsertProvider;
    import org.apache.ibatis.annotations.Options;
    import org.apache.ibatis.annotations.SelectProvider;
    import org.apache.ibatis.annotations.UpdateProvider;
    import org.fkit.domain.Employee;
    
    public interface EmployeeMapper {
        
        // 动态查询
        @SelectProvider(type=EmployeeDynaSqlProvider.class,method="selectWhitParam")
        List<Employee> selectWhitParam(Map<String, Object> param);
        
        // 动态插入
        @InsertProvider(type=EmployeeDynaSqlProvider.class,method="insertEmployee")
        @Options(useGeneratedKeys = true, keyProperty = "id")  
        int insertEmployee(Employee employee);
        
        // 根据id查询
        @SelectProvider(type=EmployeeDynaSqlProvider.class,method="selectWhitParam")
        Employee selectEmployeeWithId(Map<String, Object> param);
        
        // 动态更新
        @UpdateProvider(type=EmployeeDynaSqlProvider.class,method="updateEmployee")
        void updateEmployee(Employee employee);
    
        // 动态删除
        @DeleteProvider(type=EmployeeDynaSqlProvider.class,method="deleteEmployee")
        void deleteEmployee(Map<String, Object> param);
        
    }

2 EmployeeDynaSqlProvider

package org.fkit.mapper;
    
    
    import java.util.Map;
    import org.apache.ibatis.jdbc.SQL;
    import org.fkit.domain.Employee;
    
    public class EmployeeDynaSqlProvider {
        
        public String selectWhitParam(Map<String, Object> param){
            return new SQL(){
                {
                    SELECT("*");
                    FROM("tb_employee");
                    if(param.get("id") != null){
                        WHERE(" id = #{id} ");
                    }
                    if(param.get("loginname") != null){
                        WHERE(" loginname = #{loginname} ");
                    }
                    if(param.get("password") != null){
                        WHERE("password = #{password}");
                    }
                    if(param.get("name")!= null){
                        WHERE("name = #{name}");
                    }
                    if(param.get("sex")!= null){
                        WHERE("sex = #{sex}");
                    }
                    if(param.get("age")!= null){
                        WHERE("age = #{age}");
                    }
                    if(param.get("phone")!= null){
                        WHERE("phone = #{phone}");
                    }
                    if(param.get("sal")!= null){
                        WHERE("sal = #{sal}");
                    }
                    if(param.get("state")!= null){
                        WHERE("state = #{state}");
                    }
                    
                }
            }.toString();
        }    
        
        public String insertEmployee(Employee employee){
            
            return new SQL(){
                {
                    INSERT_INTO("tb_employee");
                    if(employee.getLoginname() != null){
                        VALUES("loginname", "#{loginname}");
                    }
                    if(employee.getPassword() != null){
                        VALUES("password", "#{password}");
                    }
                    if(employee.getName()!= null){
                        VALUES("name", "#{name}");
                    }
                    if(employee.getSex()!= null){
                        VALUES("sex", "#{sex}");
                    }
                    if(employee.getAge()!= null){
                        VALUES("age", "#{age}");
                    }
                    if(employee.getPhone()!= null){
                        VALUES("phone", "#{phone}");
                    }
                    if(employee.getSal()!= null){
                        VALUES("sal", "#{sal}");
                    }
                    if(employee.getState()!= null){
                        VALUES("state", "#{state}");
                    }
                }
            }.toString();
        }
        
        public String updateEmployee(Employee employee){
            
            return new SQL(){
                {
                    UPDATE("tb_employee");
                    if(employee.getLoginname() != null){
                        SET("loginname = #{loginname}");
                    }
                    if(employee.getPassword() != null){
                        SET("password = #{password}");
                    }
                    if(employee.getName()!= null){
                        SET("name = #{name}");
                    }
                    if(employee.getSex()!= null){
                        SET("sex = #{sex}");
                    }
                    if(employee.getAge()!= null){
                        SET("age = #{age}");
                    }
                    if(employee.getPhone()!= null){
                        SET("phone = #{phone}");
                    }
                    if(employee.getSal()!= null){
                        SET("sal = #{sal}");
                    }
                    if(employee.getState()!= null){
                        SET("state = #{state}");
                    }
                    WHERE(" id = #{id} ");
                }
            }.toString();
        }
        
        public String deleteEmployee(Map<String, Object> param){
            
            return new SQL(){
                {
                    DELETE_FROM("tb_employee");
                    if(param.get("id") != null){
                        WHERE(" id = #{id} ");
                    }
                    if(param.get("loginname") != null){
                        WHERE(" loginname = #{loginname} ");
                    }
                    if(param.get("password") != null){
                        WHERE("password = #{password}");
                    }
                    if(param.get("name")!= null){
                        WHERE("name = #{name}");
                    }
                    if(param.get("sex")!= null){
                        WHERE("sex = #{sex}");
                    }
                    if(param.get("age")!= null){
                        WHERE("age = #{age}");
                    }
                    if(param.get("phone")!= null){
                        WHERE("phone = #{phone}");
                    }
                    if(param.get("sal")!= null){
                        WHERE("sal = #{sal}");
                    }
                    if(param.get("state")!= null){
                        WHERE("state = #{state}");
                    }
                }
            }.toString();
        }
    }

**四 配置文件**

1 db.properties

driver=com.mysql.jdbc.Driver
    url=jdbc:mysql://127.0.0.1:3306/mybatis
    username=root
    password=123456

2 log4j.xml

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">  
    <log4j:configuration  xmlns:log4j="http://jakarta.apache.org/log4j/">  
        <appender name="STDOUT"  class="org.apache.log4j.ConsoleAppender">  
            <layout class="org.apache.log4j.PatternLayout">  
                <param name="ConversionPattern" value="%5p [%t] %m%n"  />  
            </layout>  
        </appender>   
         <logger name="org.fkit.mapper">  
            <level value="DEBUG" />  
        </logger>
        <root>  
            <level value="ERROR" />  
            <appender-ref ref="STDOUT" />  
        </root>  
    </log4j:configuration>

3 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>
         <properties resource="db.properties"/>
         
         <settings>
               <setting name="logImpl" value="LOG4J"/>
               
               <setting name="lazyLoadingEnabled" value="true"/>
               <setting name="aggressiveLazyLoading" value="false"/>
         </settings>
         <environments default="mysql">
         
        <environment id="mysql">
        
          <transactionManager type="JDBC"/>
          
          <dataSource type="POOLED">
            <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="org.fkit.mapper.EmployeeMapper"/>
      </mappers>
    </configuration>

**五 测试代码**

package org.fkit.test;
    
    import java.util.HashMap;
    import java.util.List;
    import java.util.Map;
    import org.apache.ibatis.session.SqlSession;
    import org.fkit.domain.Employee;
    import org.fkit.factory.FKSqlSessionFactory;
    import org.fkit.mapper.EmployeeMapper;
    public class DynamicSQLTest {
    
        public static void main(String[] args)  {
            // 定义SqlSession变量
            SqlSession sqlSession = null;
            try {
                // 创建SqlSession实例
                sqlSession = FKSqlSessionFactory.getSqlSession();
                DynamicSQLTest t = new DynamicSQLTest();
                // 获取EmployeeMapper对象
                EmployeeMapper em = sqlSession.getMapper(EmployeeMapper.class);
                // 测试testSelectWhitParam方法
                t.testSelectWhitParam(em);
                // 测试testInsertEmployee方法
    //            t.testInsertEmployee(em);
                // 测试testUpdateEmployee方法
    //            t.testUpdateEmployee(em);
                // 测试testDeleteEmployee方法
    //            t.testDeleteEmployee(em);
                // 提交事务
                sqlSession.commit();
            } catch (Exception e) {
                // 回滚事务
                sqlSession.rollback();
                e.printStackTrace();
            }finally {
                // 关闭SqlSession
                if(sqlSession != null)
                    sqlSession.close();
            }
        }
        
        // 根据动态参数查询员工数据
        public void testSelectWhitParam(EmployeeMapper em){
            // 使用Map装载参数
            Map<String, Object> param = new HashMap<String, Object>();
            param.put("loginname", "jack");
            param.put("password", "123456");
            // 调用selectWhitParam方法
            List<Employee> list = em.selectWhitParam(param);
            // 查看返回结果
            System.out.println(list);
        }
        
        // 根据设置的属性动态插入数据
        public void testInsertEmployee(EmployeeMapper em){
            
            Employee e = new Employee();
            e.setLoginname("mary");
            e.setPassword("123456");
            e.setName("玛丽");
            e.setSex("女");
            e.setAge(20);
            e.setPhone("13902019999");
            e.setSal(9800.99);
            // 注意：没有设置state属性，则insert语句中不会包含state列
            // e.setState("ACTIVE");
            em.insertEmployee(e);
            
            System.out.println("插入成功，返回id：" + e.getId());
    
        }
        
        // 根据设置的属性动态更新数据
        public void testUpdateEmployee(EmployeeMapper em){
            // 使用Map装载参数
            Map<String, Object> param = new HashMap<String, Object>();
            param.put("id", 5);
            // 查询id为1的员工
            Employee e = em.selectEmployeeWithId(param);
            // 修改员工对象的三个属性
            e.setLoginname("update");
            e.setPassword("fkjava");
            e.setName("测试");
            // 动态更新
            em.updateEmployee(e);
        }
        
        // 根据设置的属性动态删除数据
        public void testDeleteEmployee(EmployeeMapper em){
            // 使用Map装载参数
            Map<String, Object> param = new HashMap<String, Object>();
            param.put("loginname", "jack");
            param.put("password", "123456");
            // 动态删除
            em.deleteEmployee(param);
    
        }
    }

**六 测试结果**

1 增

DEBUG [main] ==>  Preparing: INSERT INTO tb_employee (loginname,  password, name, sex, age, phone, sal) VALUES (?, ?, ?, ?, ?, ?,  ?)
    DEBUG [main] ==> Parameters: mary(String), 123456(String), 玛丽(String), 女(String), 20(Integer), 13902019999(String),  9800.99(Double)
    DEBUG [main] <==    Updates: 1
    插入成功，返回id：3

2 查

DEBUG [main] ==>  Preparing: SELECT * FROM tb_employee WHERE (  loginname = ? AND password = ?)
    DEBUG [main] ==> Parameters: jack(String), 123456(String)
    DEBUG [main] <==      Total: 1
    [Employee [id=3, loginname=jack, password=123456, name=玛丽,  sex=女, age=20, phone=13902019999, sal=9800.99, state=null]]

3 改

DEBUG [main] ==>  Preparing: SELECT * FROM tb_employee WHERE (  id = ? )
    DEBUG [main] ==> Parameters: 3(Integer)
    DEBUG [main] <==      Total: 1
    DEBUG [main] ==>  Preparing: UPDATE tb_employee SET loginname =  ?, password = ?, name = ?, sex = ?, age = ?, phone = ?, sal = ?  WHERE ( id = ? )
    DEBUG [main] ==> Parameters: update(String), fkjava(String), 测试(String), 女(String), 20(Integer), 13902019999(String),  9800.99(Double), 3(Integer)
    DEBUG [main] <==    Updates: 1

4 删

DEBUG [main] ==>  Preparing: DELETE FROM tb_employee WHERE (  loginname = ? AND password = ?)
    DEBUG [main] ==> Parameters: jack(String), 123456(String)
    DEBUG [main] <==    Updates: 1