[Spring] Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-07-22 14:58:17.827 ERROR 55647 --- [  restartedMain] o.s.b.d.LoggingFailureAnalysisReporter   : 

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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).


Process finished with exit code 0

우선 이렇게 뜨는 이유는 DB설정을 하지 않아서인데요. application.properties나 application.yml에 DB정보인 url, username, password등을 설정해주시면 됩니다.

여담으로 H2같은경우 설정하지 않아도 잘 작동이 되는데 아무것도 작성하지 않으면 기본값으로 로컬 서버로 작동하므로 문제가 발생하지 않습니다. (같은 임베디스 DB인 HSQL, Derby또한 똑같이 기본값이 로컬 서버로 되는걸로 알고 있지만 사용해본적이 없어서 확답이 어렵네요....)