改造为Maven多模块项目后报错：If you want an embedded database (H2, HSQL or Derby)

情景

一个Maven单模块项目改造为多模块项目后，发现报错：

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APPLICATION FAILED TO START
***************************

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 1

一种可行的解决方案

如果是Maven多模块项目，查看IDEA右上角Edit Configurations -> Use classpath of module，此栏应为 包含程序入口的xxxApplication.java和application.yml的module：

如上图，博主的程序入口xxxApplication.java和application.yml放置于server这个module，brother-takeaway-order是之前单体模块的名称。把此处的module切换为server，即可解决报错。