标签:figure pat map spring容器 text extends 直接 curl oid
MyBatis Plus (简称MP)是国内人员开发的 MyBatis 增强工具,在 MyBatis 的基础上只做增强不做改变,为简化开发、提高效率而生。
特征
无侵入:Mybatis-Plus 在 Mybatis 的基础上进行扩展,只做增强不做改变,引入 Mybatis-Plus 不会对您现有的 Mybatis 构架产生任何影响,而且 MP 支持所有 Mybatis 原生的特性
依赖少:仅仅依赖 Mybatis 以及 Mybatis-Spring
损耗小:启动即会自动注入基本CURD,性能基本无损耗,直接面向对象操作
预防Sql注入:内置Sql注入剥离器,有效预防Sql注入攻击
通用CRUD操作:内置通用 Mapper、通用 Service,仅仅通过少量配置即可实现单表大部分 CRUD 操作,更有强大的条件构造器,满足各类使用需求
多种主键策略:支持多达4种主键策略(内含分布式唯一ID生成器),可自由配置,完美解决主键问题
框架结构
1.导入依赖
<dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus</artifactId> <version>2.0.1</version> </dependency>
2.MP整合的配置
<!-- 0.连接池属性设置读取指定的properties文件 --> <context:property-placeholder location="classpath:db.properties" ignore-unresolvable="true"/> <!-- 1.将连接池放入spring容器 --> <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="jdbcUrl" value="${jdbc.url}"></property> <property name="driverClass" value="${jdbc.driver}"></property> <property name="user" value="${jdbc.username}"></property> <property name="password" value="${jdbc.password}"></property> </bean> <bean id="sqlSessionFactory" class="com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"/> <!-- 配置实体扫描路径,多个package可以用分号; 逗号, 分隔, 支持通配符*--> <!-- com.a.b.entity;com.a.c.entity;com.d.*.entity--> <property name="typeAliasesPackage" value="cn.xm.jwxt.bean.*"/> <property name="configuration" ref="mybatisConfig"/> <!-- MP 全局配置注入 --> <property name="globalConfig" ref="globalConfig"/> <property name="plugins"> <array> <!-- 分页插件配置 --> <bean id="paginationInterceptor" class="com.baomidou.mybatisplus.plugins.PaginationInterceptor"/> <!-- 性能拦截器,兼打印sql,不建议生产环境配置--> <bean id="performanceInterceptor" class="com.baomidou.mybatisplus.plugins.PerformanceInterceptor"/> </array> </property> </bean> <bean id="mybatisConfig" class="com.baomidou.mybatisplus.MybatisConfiguration"> <property name="mapUnderscoreToCamelCase" value="true"/> </bean> <!-- 定义 MP 全局策略 --> <bean id="globalConfig" class="com.baomidou.mybatisplus.entity.GlobalConfiguration"> <property name="idType" value="2"/> <property name="dbType" value="mysql"/> <!-- 全局表为下划线命名设置 true --> <property name="dbColumnUnderline" value="true"/> </bean> <!-- 配置mybatis 扫描mapper接口的路径, 相当于注解@MapperScan,@MapperScan("com.baomidou.mybatisplus.test.h2.entity.mapper")--> <bean id="mapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="cn.xm.jwxt.mapper"/> </bean>
3.实体
@TableName(value="employee")
public class Employee { private Integer id ; private String lastName; private String email ; private Integer gender; private Integer age ; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } public Integer getGender() { return gender; } public void setGender(Integer gender) { this.gender = gender; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } @Override public String toString() { return "Employee [id=" + id + ", lastName=" + lastName + ", email=" + email + ", gender=" + gender + ", age=" + age + "]"; } }
4.mapper 接口
public interface EmployeeMapper extends BaseMapper<Employee> {}
5.新增
@Test public void testCommonInsert() { //初始化Employee对象 Employee employee = new Employee(); employee.setLastName("MP"); employee.setEmail("mp@atguigu.com"); employee.setGender(1); //insert方法在插入时,会根据实体类的每个属性进行非空判断,只有非空的属性对应的字段才会出现到SQL语句中 Integer result = employeeMapper.insert(employee); System.out.println("result: " + result ); //insertAllColumn方法在插入时,不管属性是否非空, 属性所对应的字段都会出现到SQL语句中. Integer result1 = employeeMapper.insertAllColumn(employee); System.out.println("result: " + result1 ); //获取当前数据在数据库中的主键值 Integer key = employee.getId(); System.out.println("key:" + key ); }
6.修改
@Test public void testCommonUpdate() { //初始化修改对象 Employee employee = new Employee(); employee.setId(7); employee.setLastName("王五"); employee.setEmail("xz@sina.com"); employee.setGender(0); //updateById方法在修改时,会根据实体类的每个属性进行非空判断,只有非空的属性对应的字段才会出现到SQL语句中 Integer result = employeeMapper.updateById(employee); System.out.println("result: " + result ); //updateAllColumnById方法在修改时,不管属性是否非空, 属性所对应的字段都会出现到SQL语句中. Integer result1 = employeeMapper.updateAllColumnById(employee); System.out.println("result: " + result1 ); }
7.查询
@Test public void testCommonSelect() { //1. 通过id查询 Employee employee = employeeMapper.selectById(7); System.out.println(employee); //2. 通过多个列进行查询。selectOne查询结果只能是一条,否则报错 Employee employee1 = new Employee(); employee.setLastName("王五"); employee.setGender(0); Employee result = employeeMapper.selectOne(employee1); System.out.println("result: " +result ); //3. 通过多个id进行查询 List<Integer> idList = new ArrayList<>(); idList.add(4); idList.add(5); idList.add(6); idList.add(7); List<Employee> emps = employeeMapper.selectBatchIds(idList); System.out.println(emps); //4. 通过Map封装条件查询。map中的key是数据库中字段名 Map<String,Object> columnMap = new HashMap<>(); columnMap.put("last_name", "Tom"); columnMap.put("gender", 1); List<Employee> emps1 = employeeMapper.selectByMap(columnMap); System.out.println(emps1); //5. 分页查询 List<Employee> emps2 = employeeMapper.selectPage(new Page<>(3, 2), null); System.out.println(emps2); }
8.删除
@Test public void testCommonDelete() { //1 .根据id进行删除 Integer result = employeeMapper.deleteById(13); System.out.println("result: " + result ); //2. 根据条件进行删除 Map<String,Object> columnMap = new HashMap<>(); columnMap.put("last_name", "MP"); columnMap.put("email", "mp@atguigu.com"); Integer result1 = employeeMapper.deleteByMap(columnMap); System.out.println("result: " + result1 ); //3. 批量删除 List<Integer> idList = new ArrayList<>(); idList.add(3); idList.add(4); idList.add(5); Integer result2 = employeeMapper.deleteBatchIds(idList); System.out.println("result: " + result2 ); }
标签:figure pat map spring容器 text extends 直接 curl oid
原文地址:https://www.cnblogs.com/dzlj/p/12229888.html