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).

原因：建立專案的時候我添加了資料庫元件，但是啟動時還沒有配置資料來源，所以會報錯，可以先新增

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})

然後專案成功啟動。