Spring-boot: required a bean named ‘entityManagerFactory’ that could not be found

I was getting error message like-

required a bean named ‘entityManagerFactory‘ that could not be found.

After lot of googling solve this problem.
I set manual configuration for JPA.

@Bean 
public LocalSessionFactoryBean sessionFactory() {
    LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean(); 

    return sessionFactory;
}

but JPA by default search sessionFactory by name ‘entityManagerFactory‘
so change my code as:

@Bean(name="entityManagerFactory")
public LocalSessionFactoryBean sessionFactory() {
    LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();

    return sessionFactory;
} 

For me, I’ve forgotten to remove DataSourceAutoConfiguration.class from exclusions.

So this:

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
// Main class definition

Should be:

@SpringBootApplication()
// Main class definition

Run into same issue when trying to connect spring boot to mysql database.

What saved me was adding correct version of hibernate-core to my pom file.
From hibernate onwards 5.2.0. hibernate-entitymanager is no longer needed. Hibernate-core 5.2.0 have problem with Spring Data JPA while process collection.Hibernate-core 5.2.1 and above is ok with Spring Data JPA if you are using Spring Data JPA.

<dependency>
 <groupId>org.hibernate</groupId>
 <artifactId>hibernate-core</artifactId>
 <version> 5.2.1.Final</version>
</dependency>

in our case was working fine but not for tests with @WebMvcTest

Took a while to find out but issue was:

@SpringBootApplication
@ComponentScan({"com.givenproject"})
@EntityScan("com.givenproject")
@EnableJpaRepositories("com.givenproject")
@Configuration
public class Application {

instead do:

@SpringBootApplication
@Configuration
public class Application {

and

@Configuration
@ComponentScan({"com.givenproject"})
@EntityScan(basePackages = "com.givenproject")
@EnableJpaRepositories(basePackages = "com.givenproject")
public class DataConfig {
}