原始的整合方式

1.添加依赖

 <!--mybatis起步依赖-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <!--mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.35</version>
        </dependency>
        <!--阿里巴巴连接池-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.9</version>
        </dependency>

2.在spring boot 配置文件配置连接池参数和mybatis参数

# 解决程序乱码
spring:
  http:
    encoding:
      charset: utf-8
      enabled: true
      force: true
  messages:
    encoding: UTF-8
  thymeleaf:
    cache: false #是否开启模版缓存
    check-template: true
    check-template-location: true
    enabled: true
    encoding: UTF-8
    mode: HTML5
    prefix: classpath:/templates/
    suffix: .html
  datasource:
      name: test
      url: jdbc:mysql://127.0.0.1:3306/haoyangback?characterEncoding=UTF-8
      username: root
      password: root
      # 使用druid数据源
      type: com.alibaba.druid.pool.DruidDataSource
      driver-class-name: com.mysql.jdbc.Driver
      filters: stat
      maxActive: 20
      initialSize: 1
      maxWait: 60000
      minIdle: 1
      timeBetweenEvictionRunsMillis: 60000
      minEvictableIdleTimeMillis: 300000
      validationQuery: select 'x'
      testWhileIdle: true
      testOnBorrow: false
      testOnReturn: false
      poolPreparedStatements: true
      maxOpenPreparedStatements: 20

mybatis:
  mapper-locations: classpath:mapping/*.xml #扫描mapping
  type-aliases-package: com.liqiang.entity  #别名前缀  配置类名就不用写全称了

4.添加逆向工程插件依赖

<build>
        <plugins>
            <!--mybatis逆向工程插件-->
            <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>1.3.2</version>
                <configuration>
                    <configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile>
                    <overwrite>true</overwrite>
                    <verbose>true</verbose>
                </configuration>
            </plugin>
        </plugins>
    </build>

5.添加逆向工程xml路径为上面插件配置路径下

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
    <!-- 数据库驱动:选择你的本地硬盘上面的数据库驱动包-->
    <!-- 数据库驱动:选择你的本地硬盘上面的数据库驱动包-->
    <classPathEntry  location="D:\MavenRepository\mysql\mysql-connector-java\5.1.35\mysql-connector-java-5.1.35.jar"/>
    <context id="DB2Tables"  targetRuntime="MyBatis3">
        <commentGenerator>
            <property name="suppressDate" value="true"/>
            <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
            <property name="suppressAllComments" value="true"/>
        </commentGenerator>
        <!--数据库链接URL，用户名、密码 -->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://127.0.0.1:3306/haoyangback?characterEncoding=UTF-8" userId="root" password="root">
        </jdbcConnection>
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>
        <!-- 生成模型的包名和位置-->
        <javaModelGenerator targetPackage="com.liqiang.entity" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>
        <!-- 生成映射文件的包名和位置-->
        <sqlMapGenerator targetPackage="mapping" targetProject="src/main/resources">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>
        <!-- 生成DAO的包名和位置-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.liqiang.mapper" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>
        <!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名-->
        <table tableName="address" domainObjectName="Address" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>
    </context>
</generatorConfiguration>

6.添加maven执行逆向工程插件的快捷命令

7.选中执行

则会在上面配置的下面生成实体还有Mapper和mapper.xml

public interface AddressMapper {
    int deleteByPrimaryKey(Integer id);

    int insert(Address record);

    int insertSelective(Address record);

    Address selectByPrimaryKey(Integer id);

    int updateByPrimaryKeySelective(Address record);

    int updateByPrimaryKey(Address record);
}

8.在splring boot 入口类开启mapper包扫描

@SpringBootApplication
@MapperScan("com.liqiang.mapper")
public class SpringBootHellwordApplication {

    public static void main(String[] args) {

        SpringApplication.run(SpringBootHellwordApplication.class, args);
    }
}

在Services注入Mapper则可以进行简单的增删改查

 @Resource
  AddressMapper addressMapper;

使用PageHelper

mybatis本身支持分页但是不是物理分页。mybatis的分页是查询sql服务端查询所有满足条件的数据然后通过ResultSet 跳过多少行取多少行(性能没有物理分页好)

使用PageHelper插件则是在我们原有的sql上拼接 select * from (sql) limit 1,4 分页语法

1.添加分页插件起步依赖

  <!-- 分页插件 -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper-spring-boot-starter</artifactId>
            <version>1.1.2</version>
        </dependency>

2.在spring boot 配置文件配置分页插件参数

#pagehelper
pagehelper:
    helperDialect: mysql
    reasonable: true
    supportMethodsArguments: true
    params: count=countSql
    returnPageInfo: check

3.mapper新增一个父id找到子节点id的方法

public interface AddressMapper {
    int deleteByPrimaryKey(Integer id);

    int insert(Address record);

    int insertSelective(Address record);

    Address selectByPrimaryKey(Integer id);

    int updateByPrimaryKeySelective(Address record);

    int updateByPrimaryKey(Address record);

    List<Address> selectByParentId(Integer id);
}

4.对应的mapper.xml修改

<sql id="Base_Column_List" >
    id, parentId, areaCode, areaName, areaType, geo, path, haveSub
  </sql>
  <select id="selectByParentId" resultMap="BaseResultMap" parameterType="java.lang.Integer">
    SELECT
    <include refid="Base_Column_List"/>
    from address
    where parentid= #{id,jdbcType=INTEGER}
  </select>

5.使用

       PageHelper.startPage(pageNum, pageSize);//分页

        List<Address> address=addressMapper.selectByParentId(3619);

实现原理是 pageHelper利用mybatis提供的插件开发接口进行了扩展，可以理解成 pageHelper.startPage会将参数存入线程缓存。然后pageHelper在mybatis的执行sql那一步进行拦截判断取出线程缓存如果有分页则将sql改变成分页的形式

Spring Boot-整合Mybatis(二)

原始的整合方式

使用PageHelper

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