附录 mapper.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="userMapper"> <!-- 通过id查询用户 --> <select id="selectUserById" parameterType="Integer" resultType="com.test.bean.user"> select * from user where u_id = #{id} </select> <!-- 通过名字进行模糊查询 --> <select id="selectUserByName" parameterType="String" resultType="com.test.bean.user"> <!-- 这里用用value 来接收 用其他单词会出问题 --> <!--select * from user where u_username like "%${value}%" --> <!-- ${}占位符易产生sql注入问题 尽可能多使用#{}占位符 --> select * from user where u_username like "%"#{name}"%" </select> <!--添加用户--> <insert id="insertuser" parameterType="com.test.bean.user"> <!-- 通过占位符+字段可以得到一个属性值 --> insert into user values(null,#{u_username},#{u_password},#{u_sex},#{u_createTime},#{u_cid}) <!-- 虽然运行了代码，但是数据库中不会显示保存进去，需要提交事务（jdbc）session提交 --> </insert> <!-- 修改用户 --> <update id="updateuser" parameterType="com.test.bean.user"> update user set u_username = #{u_username} where u_id =#{u_id} </update> <!-- 删除用户 --> <delete id="deleteuserbyId" parameterType="com.test.bean.user"> delete from user where u_id = #{id} </delete> </mapper>sqlConfig.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> <!-- 使用spring之后就省去 --> <environments default="development"> <environment id="development"> <!-- 使用jdbc事务 --> <transactionManager type="JDBC"/> <dataSource type="POOLED"> <!-- 使用连接池 连接数据库 --> <property name="driver" value="com.mysql.cj.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/ssm_mybatis?serverTimezone=UTC"/> <property name="username" value="root"/> <property name="password" value="123456"/> </dataSource> </environment> </environments> <mappers> <mapper resource="mapper/UserMapper.xml"/> <!--按住ctrl键 检验是否能跳转 --> </mappers> </configuration>