• sql 脚本：

-- ----------------------------
-- Table structure for account
-- ----------------------------
DROP TABLE IF EXISTS `account`;
CREATE TABLE `account`  (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_id` int(11) NULL DEFAULT NULL COMMENT '外键',
  `money` double NULL DEFAULT NULL COMMENT '存款',
  PRIMARY KEY (`id`) USING BTREE,
  INDEX `fk_user_id`(`user_id`) USING BTREE,
  CONSTRAINT `fk_user_id` FOREIGN KEY (`user_id`) REFERENCES `user` (`id`) ON DELETE RESTRICT ON UPDATE RESTRICT
) ENGINE = InnoDB AUTO_INCREMENT = 4 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of account
-- ----------------------------
INSERT INTO `account` VALUES (1, 1, 5000);
INSERT INTO `account` VALUES (2, 2, 2000);
INSERT INTO `account` VALUES (3, 3, 3000);

-- ----------------------------
-- Table structure for course
-- ----------------------------
DROP TABLE IF EXISTS `course`;
CREATE TABLE `course`  (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键',
  `name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '课程名称',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 4 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of course
-- ----------------------------
INSERT INTO `course` VALUES (1, '语文');
INSERT INTO `course` VALUES (2, '数学');
INSERT INTO `course` VALUES (3, '英语');

-- ----------------------------
-- Table structure for student
-- ----------------------------
DROP TABLE IF EXISTS `student`;
CREATE TABLE `student`  (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键',
  `name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '学生姓名',
  `age` int(11) NULL DEFAULT NULL COMMENT '学生年龄',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 3 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of student
-- ----------------------------
INSERT INTO `student` VALUES (1, '张三', 20);
INSERT INTO `student` VALUES (2, '李四', 25);

-- ----------------------------
-- Table structure for student_course
-- ----------------------------
DROP TABLE IF EXISTS `student_course`;
CREATE TABLE `student_course`  (
  `sid` int(11) NULL DEFAULT NULL COMMENT '外键，指向学生表的主键',
  `cid` int(11) NULL DEFAULT NULL COMMENT '外键，指向课程表的主键',
  INDEX `fk_sid`(`sid`) USING BTREE,
  INDEX `fk_cid`(`cid`) USING BTREE,
  CONSTRAINT `fk_cid` FOREIGN KEY (`cid`) REFERENCES `course` (`id`) ON DELETE RESTRICT ON UPDATE RESTRICT,
  CONSTRAINT `fk_sid` FOREIGN KEY (`sid`) REFERENCES `student` (`id`) ON DELETE RESTRICT ON UPDATE RESTRICT
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of student_course
-- ----------------------------
INSERT INTO `student_course` VALUES (1, 1);
INSERT INTO `student_course` VALUES (1, 2);
INSERT INTO `student_course` VALUES (1, 3);
INSERT INTO `student_course` VALUES (2, 3);

-- ----------------------------
-- Table structure for user
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user`  (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '用户名',
  `birthday` datetime(0) NULL DEFAULT NULL COMMENT '生日',
  `gender` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '性别',
  `address` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL COMMENT '地址',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 4 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES (1, '张三', '2021-11-02 10:43:06', '男', '江苏苏州');
INSERT INTO `user` VALUES (2, '李四', '2021-10-26 10:43:24', '女', '江苏南京');
INSERT INTO `user` VALUES (3, '王五', '2021-10-26 10:43:45', '男', '江苏徐州');

• 导入相关 jar 包的 Maven 坐标：

<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.4.1</version>
</dependency>
<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.17</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.21</version>
</dependency>
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.13</version>
    <scope>test</scope>
</dependency>

• 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>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                <property name="url"
                          value="jdbc:mysql://192.168.134.100:3306/test?useUnicode=true&amp;characterEncoding=UTF-8&amp;autoReconnect=true&amp;useSSL=false&amp;serverTimezone=GMT%2B8&amp;allowPublicKeyRetrieval=true"/>
                <property name="username" value="root"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <package name="com.github.mapper"/>
    </mappers>
</configuration>

• 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">
   <param name="Encoding" value="UTF-8" />
   <layout class="org.apache.log4j.PatternLayout">
    <param name="ConversionPattern" value="%-5p %d{MM-dd HH:mm:ss,SSS} %m  (%F:%L) \n" />
   </layout>
 </appender>
 <logger name="java.sql">
   <level value="debug" />
 </logger>
 <logger name="org.apache.ibatis">
   <level value="info" />
 </logger>
 <root>
   <level value="debug" />
   <appender-ref ref="STDOUT" />
 </root>
</log4j:configuration>