spring jpa mysql driver Failed to configure a DataSource: ‘url’ attribute is not specified and no embedded datasource could be configured.

if you have this error :

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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).

ERROR 29548 --- [           main] o.s.test.context.TestContextManager      : Caught exception while allowing TestExecutionListener [org.springframework.test.context.web.ServletTestExecutionListener@xxx] to prepare test instance [com.xxx@xxx]

all what you should do is to update the file application.properties to be like this

spring.datasource.url=jdbc:mysql://localhost:3306/db
spring.datasource.username=
spring.datasource.password=   
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.database-platform = org.hibernate.dialect.MySQL5Dialect
spring.jpa.generate-ddl=true
spring.jpa.hibernate.ddl-auto = update

if you had already configured datasource and you still have the error try to set

spring.datasource.driver-class-name=com.mysql.jdbc.Driver

rather than

spring.datasource.driverClassName=com.mysql.jdbc.Driver

thank you!