spring:
  datasource:
    #   数据源基本配置
    username: root
    password: 123456
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/jdbc?&useSSL=false&serverTimezone=UTC //校准时差
    initialization-mode: always //Spring Boot2.x 执行schema.sql初始化数据库

schema‐*.sql（sql建表语句）、data‐*.sql（sql数据有关语句）
默认规则：schema.sql，schema‐all.sql；
可以使用：schema: 
　　　　　　‐ classpath:department.sql 指定位置

@Controller
public class HelloController {
    @Autowired
    JdbcTemplate jdbcTemplate;
    @ResponseBody
    @GetMapping("/query")
    public Map<String,Object> map(){
        List<Map<String, Object>> list = jdbcTemplate.queryForList("select * from department");
        return list.get(0);
    }
}

type: com.alibaba.druid.pool.DruidDataSource

#   数据源其他配置
    initialSize: 5
    minIdle: 5
    maxActive: 20
    maxWait: 60000
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    poolPreparedStatements: true
    #   配置监控统计拦截的filters，去掉后监控界面sql无法统计，‘wall‘用于防火墙
    filters: stat,wall,log4j2
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

导入druid数据源
@Configuration
public class DruidConfig {
   //将自定义的属性绑定进去
    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druid(){
        return new DruidDataSource();
    }　

    @Bean
    public ServletRegistrationBean statViewServlet(){
        ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
        Map<String ,String> initParams = new HashMap<>();
        initParams.put("loginUsername","admin");   //设置登录名称
        initParams.put("loginPassword","123456");  //设置登录密码
        initParams.put("allow","");                //默认是允许所有访问
        initParams.put("deny","10.81.255.181");    //设置禁止访问对象
        bean.setInitParameters(initParams);
        return bean;
    }

    @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>2.1.3</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 void delDeptById(Integer id);
    @Options(useGeneratedKeys = true,keyProperty = "id")          //获取自增id
    @Insert("insert into department(department_name) values(#{departmentName})")
    public void insertDept(Department department);
    @Update("update department set department_name = #{departmentName} where id = #{id}")
    public void 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);
            }
        };
    }
}

package com.example.springbootdatamybatis;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan(value = "com.example.springbootdatamybatis.mapper")  //mapper包下的其所有都自动添加了注解
@SpringBootApplication
public class SpringbootDataMybatisApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringbootDataMybatisApplication.class, args);
    }

}

<?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="${driver}"/>
        <property name="url" value="${url}"/>                     //去掉这块内容
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
      </dataSource>
    </environment>
  </environments>
  <mappers>
    <mapper resource="org/mybatis/example/BlogMapper.xml"/>
  </mappers>
</configuration>

<?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="com.example.springbootdatamybatis.mapper.EmployeeMapper">  //和接口绑定
    <!--public Employee getEmpById(Integer id);

    public void insertEmp(Employee employee);-->
    <select id="getEmpById" resultType="com.example.springbootdatamybatis.bean.Employee">         //配置方法
        select * from employee where id = #{id}
    </select>
    <insert id="insertEmp" useGeneratedKeys="true" keyProperty="id">
        insert into employee(lastName,email,gender,d_id) values (#{lastName},#{email},#{gender},#{dId})
    </insert>
</mapper>

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

<?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>
    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>    //驼峰命名法开启
    </settings>
</configuration>