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: ${base.package}.model
configuration:
map-underscore-to-camel-case: true
# 二级缓存的总开关
cache-enabled: false
mapper-locations: classpath:mapping/*.xml2. 新增数据源配置类
/**
-
数据源配置
-
@author simon
@date 2019-02-18
*/
@Configuration
public class DataSourceConfig {
@Value("${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
<<span class="hljs-keyword">select</span> id=<span class="hljs-string">"findAuthorityByUrl"</span> resultType=<span class="hljs-string">"java.lang.String"</span> databaseId=<span class="hljs-string">"postgresql"</span>>
<span class="hljs-function">SELECT
<span class="hljs-title">string_agg</span>(<span class="hljs-params"> tsma.authority, <span class="hljs-string">','</span></span>) <span class="hljs-keyword">as</span> authority
FROM
t_side_menu tsm
LEFT JOIN t_side_menu_authority tsma ON tsm.id</span> = tsma.side_menu_id
</<span class="hljs-keyword">select</span>></code></pre>
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。
原文地址：https://segmentfault.com/a/1190000018193491?utm_source=tag-newest </div>