Failed to configure a DataSource

情景再现

第一个springboot项目启动报错Failed to configure a DataSource: 'url' attribute is not specified and no embedde

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APPLICATION FAILED TO START
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Description:
Failed to configure a DataSource: 'url' attribute is not specified and no     embedded datasource could be configured.
Reason: Failed to determine a suitable driver class
Action:
Consider the following:
If you want an embedded database (H2, HSQL or Derby), please put it on the classpath.
If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).

解决方法：

@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)

@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
public class DemoApplication {
public static void main(String[] args) {
    SpringApplication.run(DemoApplication.class, args);
  }
}