两种数据库连接方式两种注解（注解版usermapper，文件版）

一、两种连接数据库的方式

方式一&＃xff1a;

springboot默认配置了&＃xff08;DataSource和sqlsessionfactory&＃xff09;

直接配置文件application.yml

里面写

spring:datasource:url: jdbc:mysql://127.0.0.1:3306/o2odb?serverTimezone&＃61;UTC&characterEncoding&＃61;utf-8&useSSL&＃61;truedriver-class-name: com.mysql.jdbc.Driverusername: rootpassword: root


方式二&＃xff1a;

类似springmvc 配置datasource和 sessionfactory&＃xff0c;然后 写入一个bean加入到容器。

application.properties里面如下


jdbc.driver&＃61;com.mysql.jdbc.Driver
jdbc.url&＃61; jdbc:mysql://localhost:3306/o2odb?useUnicode&＃61;true&characterEncoding&＃61;utf8
jdbc.username&＃61;root
jdbc.password&＃61;root

然后新建两个config


import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;import java.beans.PropertyVetoException;&＃64;Configuration
&＃64;MapperScan("com.hy.xx.dao")public class DataSourceConfiguration {&＃64;Value("${jdbc.driver}")private String jdbcDriver;&＃64;Value("${jdbc.url}")private String jdbcUrl;&＃64;Value("${jdbc.username}")private String jdbcUsername;&＃64;Value("${jdbc.password}")private String jdbcPassword;&＃64;Bean(name &＃61; "dataSource")public ComboPooledDataSource createDataSource() throws PropertyVetoException {ComboPooledDataSource dataSource &＃61; new ComboPooledDataSource();//dirverdataSource.setDriverClass(jdbcDriver);//urldataSource.setJdbcUrl(jdbcUrl);//usernamedataSource.setUser(jdbcUsername);//passworddataSource.setPassword(jdbcPassword);//在关闭连接之后不会自动的CommitdataSource.setAutoCommitOnClose(false);// dataSource.setAcquireIncrement(5);// dataSource.setAcquireRetryAttempts(30);// dataSource.setAcquireRetryDelay(1000);// dataSource.setInitialPoolSize(10);dataSource.setMinPoolSize(5);// dataSource.setMaxPoolSize(200);// dataSource.setMaxIdleTime(60);//dataSource.setMaxIdleTimeExcessConnections(600);return dataSource;}}


import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;import javax.sql.DataSource;
import java.io.IOException;&＃64;Configuration
public class SessionFactoryConfiguration {&＃64;Autowiredprivate DataSource dataSource;&＃64;Bean(name&＃61;"sqlSessionFactory")public SqlSessionFactoryBean createSqlSessionFactoryBean() throws IOException{SqlSessionFactoryBean bean &＃61; new SqlSessionFactoryBean();//加载主配置文件mybatis-config.xmlbean.setConfigLocation(new ClassPathResource("mybatis-config.xml"));//Mapper扫描路径PathMatchingResourcePatternResolver resolver &＃61; new PathMatchingResourcePatternResolver();String packageSearchPath &＃61; "classpath*:/mapper/**.xml";bean.setMapperLocations(resolver.getResources(packageSearchPath));//配置实体的包bean.setTypeAliasesPackage("com.hy.oa.model");//dataSourcebean.setDataSource(dataSource);return bean;}}


启动即可。

二、两种和数据库打交道

&＃64;RestController
public class wenjianversioncontroller {&＃64;Autowiredprivate UserDao userDao;&＃64;RequestMapping("/wenjianfindall")public String wenjianfindall(){List users &＃61; userDao.searchAllUsers();for (User user : users) {System.out.println(user.getId()&＃43;"--"&＃43;user.getUsername()&＃43;""&＃43;user.getPassword());}userDao.deleteUserById(2);return "wenjianfindall";}


public interface UserDao {//增int addUser(User user);//删//int deletUser(User user);int deleteUserById(int id);//改int updateUser(User user);//查List searchAllUsers();User searchUserById(int id);
}


然后resource里面的mapper里面



select * from userselect * from user where id &＃61; #{id}insert into user values(#{id},#{username},#{password})update user set username&＃61;#{username},password&＃61;#{password} where id&＃61;#{id}delete from user where id &＃61; #{id}

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方式二&＃xff1a;

dao里面直接注解&＃xff0c;然后注解里面写sql语句。

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;import java.util.List;
&＃64;Mapper
public interface UserMapper {&＃64;Select("select * from user")List findAll();
}


public class TestController {&＃64;Autowiredprivate UserMapper userMapper;&＃64;RequestMapping("/findAll")public String findall(){List userList &＃61; userMapper.findAll();for(User user : userList){System.out.println(user.getId()&＃43;""&＃43;user.getUsername()&＃43;""&＃43;user.getPassword());}return "hello";}}