Mybatis入门（二）

一、利用resultMap 复杂类型映射

1、一对一

DROP TABLE IF EXISTS `car`;
CREATE TABLE `car` (
  `cid` int(11) NOT NULL AUTO_INCREMENT,
  `cname` varchar(20) DEFAULT NULL,
  `pid` int(11) NOT NULL,
  PRIMARY KEY (`cid`),
  KEY `cp` (`pid`),
  CONSTRAINT `cp` FOREIGN KEY (`pid`) REFERENCES `person` (`Id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;

INSERT INTO `car` VALUES (1, '忆柳的购物车', 2);
INSERT INTO `car` VALUES (2, '梦琪的购物车', 1);
INSERT INTO `car` VALUES (3, '新柔的购物车', 5);
INSERT INTO `car` VALUES (4, '慕青的购物车', 3);
INSERT INTO `car` VALUES (5, '初夏的购物车', 4);

2、一对多

DROP TABLE IF EXISTS `orders`;
CREATE TABLE orders (
  `oid` int(11) NOT NULL AUTO_INCREMENT,
  `oname` varchar(255) DEFAULT NULL,
  `pid` int(11) DEFAULT NULL,
  PRIMARY KEY (`oid`),
  KEY `op` (`pid`),
  CONSTRAINT `op` FOREIGN KEY (`pid`) REFERENCES `person` (`Id`)
) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=utf8;

INSERT INTO `orders` VALUES (1, '荣耀MagicBook 2019 14英寸轻薄窄边框', 2);
INSERT INTO `orders` VALUES (2, '小米 (MI)Ruby 2019款 15.6英寸金属轻薄', 1);
INSERT INTO `orders` VALUES (3, '戴尔灵越14 燃 14英寸英特尔酷睿i5轻薄窄边框', 3);
INSERT INTO `orders` VALUES (4, '联想(Lenovo)小新14英寸 锐龙版R5', 4);
INSERT INTO `orders` VALUES (5, '红辣椒7X 4+64GB 学生智能手机', 5);
INSERT INTO `orders` VALUES (6, '荣耀10青春版 幻彩渐变', 1);
INSERT INTO `orders` VALUES (7, 'OPPO K1 全面屏手机', 2);
INSERT INTO `orders` VALUES (8, '卡梵蒂GAVADI 鳄鱼皮钱包', 5);
INSERT INTO `orders` VALUES (9, '七匹狼钱包', 2);
INSERT INTO `orders` VALUES (10, '金利来（Goldlion）男士钱包', 1);

3、多对多

#学生表
DROP TABLE IF EXISTS `student`;
CREATE TABLE `student` (
  `sid` int(11) NOT NULL AUTO_INCREMENT,
  `sname` varchar(20) DEFAULT NULL,
  PRIMARY KEY (`sid`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

INSERT INTO `student` VALUES (1, '梦琪');
INSERT INTO `student` VALUES (2, '初夏');
INSERT INTO `student` VALUES (3, '忆柳');
#课程表
DROP TABLE IF EXISTS `course`;
CREATE TABLE `course` (
  `cid` int(11) NOT NULL AUTO_INCREMENT,
  `cname` varchar(20) DEFAULT NULL,
  PRIMARY KEY (`cid`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

INSERT INTO `course` VALUES (1, 'JAVA');
INSERT INTO `course` VALUES (2, 'HTML');
INSERT INTO `course` VALUES (3, 'DATABASE');
#中间表
DROP TABLE IF EXISTS `stu_cou`;
CREATE TABLE `stu_cou` (
  `scid` int(11) NOT NULL AUTO_INCREMENT,
  `cid` int(11) DEFAULT NULL,
  `sid` int(11) DEFAULT NULL,
  PRIMARY KEY (`scid`),
  KEY `scs` (`sid`),
  KEY `scc` (`cid`),
  CONSTRAINT `scc` FOREIGN KEY (`cid`) REFERENCES `course` (`cid`),
  CONSTRAINT `scs` FOREIGN KEY (`sid`) REFERENCES `student` (`sid`)
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8;

INSERT INTO `stu_cou` VALUES (1, 1, 1);
INSERT INTO `stu_cou` VALUES (2, 1, 2);
INSERT INTO `stu_cou` VALUES (3, 1, 3);
INSERT INTO `stu_cou` VALUES (4, 2, 1);
INSERT INTO `stu_cou` VALUES (5, 2, 2);
INSERT INTO `stu_cou` VALUES (6, 2, 3);
INSERT INTO `stu_cou` VALUES (7, 3, 1);

二、动态sql构建

三、 延迟加载

四、缓存技术

五、mybatis的反向工程

六、#{}和${}的使用