第六章-Spring Boot 数据访问

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

spring:
  datasource:
    username: root
    password: 123456
    url: jdbc:mysql://192.168.15.22:3306/jdbc
    driver-class-name: com.mysql.jdbc.Driver

org.apache.tomcat.jdbc.pool.DataSource、HikariDataSource、BasicDataSource、

/**
 * Generic DataSource configuration.
 */
@ConditionalOnMissingBean(DataSource.class)
@ConditionalOnProperty(name = "spring.datasource.type")
static class Generic {
​
   @Bean
   public DataSource dataSource(DataSourceProperties properties) {
       //使用DataSourceBuilder创建数据源，利用反射创建响应type的数据源，并且绑定相关属性
      return properties.initializeDataSourceBuilder().build();
   }
​
}

schema-*.sql、data-*.sql
默认规则：schema.sql，schema-all.sql；
可以使用   
    schema:
      - classpath:department.sql
      指定位置

导入druid数据源
@Configuration
public class DruidConfig {
​
    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druid(){
       return  new DruidDataSource();
    }
​
    //配置Druid的监控
    //1、配置一个管理后台的Servlet
    @Bean
    public ServletRegistrationBean statViewServlet(){
        ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
        Map<String,String> initParams = new HashMap<>();
​
        initParams.put("loginUsername","admin");
        initParams.put("loginPassword","123456");
        initParams.put("allow","");//默认就是允许所有访问
        initParams.put("deny","192.168.15.21");
​
        bean.setInitParameters(initParams);
        return bean;
    }
​
​
    //2、配置一个web监控的filter
    @Bean
    public FilterRegistrationBean webStatFilter(){
        FilterRegistrationBean bean = new FilterRegistrationBean();
        bean.setFilter(new WebStatFilter());
​
        Map<String,String> initParams = new HashMap<>();
        initParams.put("exclusions","*.js,*.css,/druid/*");
​
        bean.setInitParameters(initParams);
​
        bean.setUrlPatterns(Arrays.asList("/*"));
​
        return  bean;
    }
}
​

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>

//指定这是一个操作数据库的mapper
@Mapper
public interface DepartmentMapper {
​
    @Select("select * from department where id=#{id}")
    public Department getDeptById(Integer id);
​
    @Delete("delete from department where id=#{id}")
    public int deleteDeptById(Integer id);
​
    @Options(useGeneratedKeys = true,keyProperty = "id")
    @Insert("insert into department(departmentName) values(#{departmentName})")
    public int insertDept(Department department);
​
    @Update("update department set departmentName=#{departmentName} where id=#{id}")
    public int updateDept(Department department);
}

@org.springframework.context.annotation.Configuration
public class MyBatisConfig {
​
    @Bean
    public ConfigurationCustomizer configurationCustomizer(){
        return new ConfigurationCustomizer(){
​
            @Override
            public void customize(Configuration configuration) {
                configuration.setMapUnderscoreToCamelCase(true);
            }
        };
    }
}

使用MapperScan批量扫描所有的Mapper接口；
@MapperScan(value = "com.atguigu.springboot.mapper")
@SpringBootApplication
public class SpringBoot06DataMybatisApplication {
​
    public static void main(String[] args) {
        SpringApplication.run(SpringBoot06DataMybatisApplication.class, args);
    }
}

mybatis:
  config-location: classpath:mybatis/mybatis-config.xml 指定全局配置文件的位置
  mapper-locations: classpath:mybatis/mapper/*.xml  指定sql映射文件的位置

//使用JPA注解配置映射关系
@Entity //告诉JPA这是一个实体类（和数据表映射的类）
@Table(name = "tbl_user") //@Table来指定和哪个数据表对应;如果省略默认表名就是user；
public class User {
​
    @Id //这是一个主键
    @GeneratedValue(strategy = GenerationType.IDENTITY)//自增主键
    private Integer id;
​
    @Column(name = "last_name",length = 50) //这是和数据表对应的一个列
    private String lastName;
    @Column //省略默认列名就是属性名
    private String email;

//继承JpaRepository来完成对数据库的操作
public interface UserRepository extends JpaRepository<User,Integer> {
}

spring:  
 jpa:
    hibernate:
#     更新或者创建数据表结构
      ddl-auto: update
#    控制台显示SQL
    show-sql: true