Mybatis增删改查，Demo整合

第一步:MyBatis的Jar包引入
mybatis-3.2.7.jar
mysql-connector-java-5.1.8.jar

MyBatis的pom.xml依赖

    <dependencies>
        <!-- jstl -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

        <!-- servlet-api -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>

        <!-- junit -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

        <!-- mybatis依赖 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.2.7</version>
        </dependency>

        <!-- mysql-connector-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.8</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <!-- JDK配置 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.5</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>UTF-8</encoding>
                </configuration>
            </plugin>

            <!-- Tomcat配置 -->
            <plugin>
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <configuration>
                    <port>8081</port>
                    <path>/</path>
                </configuration>
            </plugin>
        </plugins>
    </build>

　　

第二步：引入log4j.properties日志文件

# Global logging configuration
log4j.rootLogger=DEBUG, stdout

# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

第三步：创建sqlMapConfig.xml文件

<?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">

	<!-- MyBatis的配置文件信息 -->
	<configuration>
		<!-- 和spring整合后 environments配置将废除 -->
		<environments default="development">
			<environment id="development">
			　　 <!-- 使用jdbc事务管理 -->
			　　<transactionManager type="JDBC"></transactionManager>
			　　<!-- 数据库连接池 -->
			　　<dataSource type="POOLED">
			 　　   <property name="driver" value="com.mysql.jdbc.Driver" />
			 　　   <property name="url"  value="jdbc:mysql://localhost:3306/test06?characterEncoding=utf-8" />
			  　　  <property name="username" value="root" />
			  　　  <property name="password" value="root" />
			　　</dataSource>
			</environment>
		</environments>
		
		<!-- 加载mapper映射文件 -->
		<mappers>
			<mapper resource="com/baidu/mapper/UserMapper.xml"/>
		</mappers>
</configuration>

第四步：创建用户实体类User类

/**
	 * 用户实体类
	 * @author Administrator
	 */
	public class User {
		private int id;
		private String name;// 用户姓名
		private Date birthday;// 生日
		private char sex;// 性别
		private String address;// 地址
		
		public int getId() {
			return id;
		}
		public void setId(int id) {
			this.id = id;
		}
		public String getName() {
			return name;
		}
		public void setName(String name) {
			this.name = name;
		}
		public Date getBirthday() {
			return birthday;
		}
		public void setBirthday(Date birthday) {
			this.birthday = birthday;
		}
		public char getSex() {
			return sex;
		}
		public void setSex(char sex) {
			this.sex = sex;
		}
		public String getAddress() {
			return address;
		}
		public void setAddress(String address) {
			this.address = address;
		}
		public User(int id, String name, Date birthday, char sex, String address) {
			super();
			this.id = id;
			this.name = name;
			this.birthday = birthday;
			this.sex = sex;
			this.address = address;
		}
		public User() {
			super();
			// TODO Auto-generated constructor stub
		}
		
		
		@Override
		public String toString() {
			return "User [id=" + id + ", name=" + name + ", birthday=" + birthday + ", sex=" + sex + ", address=" + address
					+ "]";
		}
	}

第五步：创建User实体类的映射文件UserMapper.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：命名空间，用于隔离sql, 命名空间 user.findUserById-->
    <mapper namespace="user">
       
　　　　增删改查SQL语句

    </mapper>

第六步：MyBatis的测试类

/**
 * 测试类
 * @author Administrator
 *
 */
public class MybatisTest1 {
	public static void main(String[] args) throws Exception {
		//加载MyBatis的核心配置文件
		String resource  = "sqlMapConfig.xml";
		//获取输入流
		InputStream resourceAsStream = Resources.getResourceAsStream(resource);
		//创建sqlSessionFactory工厂
		SqlSessionFactory sf = new SqlSessionFactoryBuilder().build(resourceAsStream);
		 //创建sqlSession
		SqlSession session = sf.openSession();
		
		//执行增删改查SQL语句

} }

增删改查SQL语句&&执行增删改查SQL语句

• 通过ID查询一个用户

  •  <!-- 通过ID查询一个用户
             id名字，namespace+id用来定位具体的sql
             parameterType：  指定输入参数类型
             resultType：返回值，指定sql输出结果的所映射的java对象类型，如果bean与数据库一一对应，则会自动映射
             where id=#{v}，#{} 占位符，里面要写一个任意字符
            -->
            <select id="findUserById" parameterType="Integer" resultType="com.mqf.entity.User">
                <!-- 如果用${value}传参，默认没有单引号，如果用#{id}传参，默认带有单引号 -->
                SELECT * FROM tb_user WHERE id = #{id};
            </select>

  •  //执行sql语句(查询单条数据方法1)
            User user = session.selectOne("user.findUserById",1);
            System.out.println(user+"==========================");
    

    　　

• 全查询

  • • <!-- 全查询 -->
      <select id="selectAllUser"  resultType="com.mqf.entity.User">
              SELECT * FROM tb_user;
      </select>

    • //全查询
      List<User> list = session.selectList("user.selectAllUser");
      if (list.size()>0 && null!=list){
          for (User user1 :list){
              System.out.println(user1+"==========================");
              //关闭连接
              session.close();
          }
      }else{
          System.out.println("查询异常！");
      }*/

• 模糊查询

  • • <!--模糊查询-->
           <!-- 根据名字模糊查询
      #{}  1.相当于？   =='' 会带单引号   2.里面的表示字符任意
      ${}     1.不带单引号    2.里面的字符必须为value
      resultType="com.ali.pojo.User"  写的是list的泛型
          -->
           <select id="selectUserName" parameterType="String" resultType="com.mqf.entity.User">
               <!--  select * from t_user where name like "%"#{name}"%"-->
                   SELECT * FROM tb_user where name like '%${value}%'
           </select>

    • //模糊查询
      /* List<User> list = session.selectList("user.selectUserName", "一");
       System.out.println(list+"======================================");*/

• 添加用户信息

  • • <!-- 添加用户信息 -->
      <insert id="insertUser" parameterType="com.mqf.entity.User"  useGeneratedKeys="true" keyProperty="id">
          /*
          将插入数据的主键，返回到user对象中
          SELECT LAST_INSERT_ID();  得到下面insert进去记录的主键值，只适用于主键自增
      
          keyProperty：将查询到主键值设置到parameterType指定的对象的id属性
          order： SELECT LAST_INSERT_ID();执行顺序，相对于insert语句来说它的执行顺序之后
          resultType：指定 SELECT LAST_INSERT_ID();的结果类型
          */
          /*
          使用mysql的uuid（）生成主键
          执行过程：
          首先通过uuid（）得到主键，将主键设置到user对象的id属性中
          其次在insert执行时，从user对象中取出id属性值
          <selectKey keyProperty="id" order="BEFORE" resultType="Integer">
              SELECT uuid();
          </selectKey>
          INSERT INTO tb_user SET id = {id},name = #{name},birthday = #{birthday},sex = #{sex},address = #{address};
           */
          <selectKey keyProperty="id" order="AFTER" resultType="Integer">
              SELECT LAST_INSERT_ID();
          </selectKey>
          INSERT INTO tb_user SET name = #{name},birthday = #{birthday},sex = #{sex},address = #{address};
      </insert>

    • //添加用户信息
       //第一步：实例化对象
      /* User user1 = new User();
       user1.setName("锡纸烫");
       user1.setSex('男');
       user1.setBirthday(new Date());
       user1.setAddress("河南安阳");
       //第二步：要session操作sql语句
       int i = session.insert("user.insertUser", user1);
       //第三步：事务提交
       session.commit();
       //判断返回值
       if (i > 0) {
           System.out.println("添加成功！");
           System.out.println(user1.getId()+"====================");
       }else {
           System.out.println("添加失败！");
       }*/

• 添加用户信息 (批量)

  • • <!-- 添加用户信息 (批量)-->
      <insert id="insertUsers" parameterType="List">
          INSERT INTO tb_user(name,birthday,sex,address) VALUES
          <foreach collection="list" item="user" index="index" separator=",">
              (#{user.name},#{user.birthday},#{user.sex},#{user.address});
          </foreach>
      </insert>

    •  /**
             * 批量添加用户信息
             */
       /*  User user1 = new User();
         user1.setName("Duck");
         user1.setBirthday(new Date());
         user1.setSex('男');
         user1.setAddress("郑州");
      
      User user2 = new User();
      user2.setName("Duck");
      user2.setBirthday(new Date());
      user2.setSex('男');
      user2.setAddress("郑州");
      
      List<User> list = new ArrayList<>();
      list.add(user1);
      list.add(user2);
      
      System.out.println(list+"+================");
      int i = session.insert("user.insertUsers", list);
      //提交事务
      session.commit();
      
        if (i>0) {
            System.out.println("添加成功！");
            //关闭连接
            session.close();
         }else {
            System.out.println("添加失败！");
            //关闭连接
            session.close();
         }*/

• 添加用户信息并返回添加用户主键id

  • • <!-- 添加用户信息并返回添加用户主键id -->
       <insert id="insertUser" parameterType="com.mqf.entity.User" useGeneratedKeys="true" keyProperty="id">
          INSERT INTO tb_user SET name = #{name},birthday = #{birthday},sex =#{sex},address = #{address};
      </insert>

    • /**
       * 添加用户信息并返回添加用户主键id
       */
      User user1 = new User();
      user1.setName("Duck1");
      user1.setBirthday(new Date());
      user1.setSex('男');
      user1.setAddress("郑州");
      int i = session.insert("user.insertUser", user1);
      //提交事务
      session.commit();
      
      if (i>0) {
          System.out.println("添加成功！");
          System.err.println(user1.getId()+"==========================");
          //关闭连接
          session.close();
      }else {
          System.out.println("添加失败！");
          //关闭连接
          session.close();
      }

• 删除用户信息(单删)

  • • <!--删除用户信息(单删)-->
      <delete id="deleteUserById" parameterType="com.mqf.entity.User">
          delete from tb_user where  id = #{id};
      </delete>

    • //删除用户信息(单删)
      /* int delete = session.delete("user.deleteUserById", 2);
       System.out.println(delete+"===================================");*/

• 删除用户信息(批删)

  • • <!--删除用户信息(批删)-->
      <delete id="deleteUserByIds" parameterType="int[]" >
          DELETE FROM tb_user WHERE id IN
          <!-- collection一般用到的值array、list、map。。。-->
          <foreach collection="array" item="array" index="no" open="("  separator=","  close=")">
              #{array}
          </foreach>
      </delete>

    • //删除用户信息(批删)
      /*int[] array = {3,4};
      int i = session.delete("user.deleteUserByIds", array);
      //提交事务
      session.commit();
      if (i > 0) {
          System.out.println("删除成功！");
          //关闭连接
          session.close();
      }else {
          System.out.println("删除失败！");
          //关闭连接
          session.close();
      }*/

• 修改用户信息　　

  • • <!--修改用户信息-->
      <update id="updataUserById" parameterType="List" >
          update  tb_user set name = #{name} where  id = #{id};
      </update>

    • //修改用户信息
      //第一步，实例化对象
      /*User user2 = new User();
      user2.setId(1);
      user2.setName("李二蛋");
      //第二步，执行修改
      int update = session.update("user.updataUserById", user2);
      //第三步，提交事务
      session.commit();
      if (update>0) {
          System.out.println("修改成功！");
          //关闭连接
          session.close();
      }else {
          System.out.println("修改失败！");
          //关闭连接
          session.close();
      }*/

以上就是简单增删改查的总结的小项目。