Spring Boot MyBatis配置多种数据库

mybatis-config.xml是支持配置多种数据库的，本文将介绍在Spring Boot中使用配置类来配置。

1. 配置application.yml

# mybatis配置

mybatis:

  check-config-location: false

  type-aliases-package: ${base.package}.model

  configuration:

    map-underscore-to-camel-case: true

    # 二级缓存的总开关

    cache-enabled: false

  mapper-locations: classpath:mapping/*.xml

2. 新增数据源配置类

/**

 * 数据源配置

 * @author simon

 * @date 2019-02-18

 */

@Configuration

public class DataSourceConfig {

    @Value("${mybatis.mapper-locations}")

    private String mapperLocations;

    @Primary

    @Bean

    @ConfigurationProperties("spring.datasource.druid")

    public DataSource dataSource(){

        return DruidDataSourceBuilder.create().build();

    }

    @Bean

    public JdbcTemplate jdbcTemplate(){

        return new JdbcTemplate(dataSource());

    }

    @Bean

    public DatabaseIdProvider databaseIdProvider(){

        DatabaseIdProvider databaseIdProvider = new VendorDatabaseIdProvider();

        Properties p = new Properties();

        p.setProperty("Oracle", "oracle");

        p.setProperty("MySQL", "mysql");

        p.setProperty("PostgreSQL", "postgresql");

        p.setProperty("DB2", "db2");

        p.setProperty("SQL Server", "sqlserver");

        databaseIdProvider.setProperties(p);

        return databaseIdProvider;

    }

    @Bean

    public SqlSessionFactoryBean sqlSessionFactoryBean() throws Exception {

        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();

        factoryBean.setDataSource(dataSource());

        factoryBean.setDatabaseIdProvider(databaseIdProvider());

        factoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(mapperLocations));

        return factoryBean;

    }

}

3. 在mapper.xml中使用

方法1

  <select id="findAuthorityByUrl" resultType="java.lang.String" databaseId="mysql">

    SELECT

      group_concat( tsma.authority ) as authority

    FROM

        t_side_menu tsm

        LEFT JOIN t_side_menu_authority tsma ON tsm.id = tsma.side_menu_id

  </select>

    <select id="findAuthorityByUrl" resultType="java.lang.String" databaseId="postgresql">

        SELECT

        string_agg( tsma.authority, ',') as authority

        FROM

        t_side_menu tsm

        LEFT JOIN t_side_menu_authority tsma ON tsm.id = tsma.side_menu_id

    </select>

方法2

  <select id="selectByPids" parameterType="String" resultMap="SuperResultMap">

    SELECT

        tsm.*,

      <if test="_databaseId == 'mysql'">

          group_concat( tsma.authority ) as authority

      </if>

      <if test="_databaseId == 'postgresql'">

          string_agg( tsma.authority, ',') as authority

      </if>

    FROM

        t_side_menu tsm

        LEFT JOIN t_side_menu_authority tsma ON tsm.id = tsma.side_menu_id

    WHERE pid IN (#{pids})

    GROUP BY

        tsm.id

  </select>

题外话

如果有兴趣，请给oauthserer项目一个star。oauthserver是一个基于Spring Boot Oauth2的完整的独立的Oauth2 Server微服务。项目的目的是，仅仅需要创建相关数据表，修改数据库的连接信息，你就可以得到一个Oauth2 Server微服务。

Spring Boot MyBatis配置多种数据库的相关教程结束。