1.Mybatis的全局配置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="jdbc.properties" />
    <settings>
        <!-- 开启驼峰匹配 -->
        <setting name="mapUnderscoreToCamelCase" value="true" />
    </settings>
    <typeAliases>
        <!-- 设置别名 -->
         <typeAlias type="cn.itcast.mybatis.pojo.User" alias="User"/> 
        <!-- <package name="cn.itcast.mybatis.pojo.User" alias="User"/> -->
    </typeAliases>
    
    <plugins>
        <!-- 通用Mapper插件 -->
        <plugin interceptor="com.github.abel533.mapperhelper.MapperInterceptor">
            <!--主键自增回写方法,默认值MYSQL,详细说明请看文档-->
            <property name="IDENTITY" value="MYSQL"/>
            <!--序列的获取规则,使用{num}格式化参数，默认值为{0}.nextval，针对Oracle-->
            <!--可选参数一共3个，对应0,1,2,分别为SequenceName，ColumnName,PropertyName-->
            <!-- <propertyname="seqFormat" value="{0}.nextval"/> -->
            <!--通用Mapper接口，多个通用接口用逗号隔开-->
            <property name="mappers" value="com.github.abel533.mapper.Mapper"/>
        </plugin>
        <!-- 分页查询插件 -->
        <plugin interceptor="com.github.pagehelper.PageHelper">
            <property name="dialect" value="mysql"/>
            <!-- 设置为true时，使用RowBounds分页会进行count查询，查询数据总条数 -->
            <property name="rowBoundsWithCount" value="true"/>
        </plugin>
    </plugins>

    <!-- 配置数据库连接的环境 -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC" />
            <dataSource type="POOLED">
                <property name="driver" value="${jdbc.driver}" />
                <property name="url" value="${jdbc.url}" />
                <property name="username" value="${jdbc.username}" />
                <property name="password" value="${jdbc.password}" />
            </dataSource>
        </environment>
    </environments>
    
    <mappers>
        <!-- 引入Mapper.xml -->
        <!-- <mapper resource="UserMapper.xml" /> -->
        
        <package name="cn.itcast.mybatis.mapper"/>
    </mappers>
</configuration>

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">
<mapper namespace="cn.itcast.mybatis.mapper.UserMapper">
    <select id="queryUserById" resultType="User">
        SELECT * FROM tb_user WHERE id = #{id};
    </select>
    <select id="queryByUserNameAndPassword" resultType="User">
        SELECT * from tb_user where user_name=#{userName} AND password=#{password};
    </select>
    
    <insert id="saveUser" useGeneratedKeys="true" keyColumn="id" keyProperty="id">
        INSERT INTO tb_user(
                                user_name,
                                password,
                                name,
                                age,
                                sex,
                                birthday,
                                created,
                                updated
                                )VALUES(
                                #{userName},
                                #{password},
                                #{name},
                                #{age},
                                #{sex},
                                #{birthday},
                                NOW(),
                                NOW()
                                );
        
    </insert>
    
    <update id="updateUser" >
        UPDATE tb_user
            SET  
             user_name =#{userName}, 
             password =#{password}, 
             name =#{name}, 
             updated =Now()
        WHERE  id =#{id};
        
    </update>
    
    <delete id="deleteById">
        DELETE FROM tb_user WHERE id=#{id};
    </delete>
</mapper>