org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set

First remove all of your configuration Spring Boot will start it for you.

Make sure you have an application.properties in your classpath and add the following properties.

spring.datasource.url=jdbc:postgresql://localhost:5432/teste?charSet=LATIN1
spring.datasource.username=klebermo
spring.datasource.password=123

spring.jpa.database-platform=org.hibernate.dialect.PostgreSQLDialect
spring.jpa.show-sql=false
spring.jpa.hibernate.ddl-auto=create

If you really need access to a SessionFactory and that is basically for the same datasource, then you can do the following (which is also documented here although for XML, not JavaConfig).

@Configuration        
public class HibernateConfig {

    @Bean
    public HibernateJpaSessionFactoryBean sessionFactory(EntityManagerFactory emf) {
         HibernateJpaSessionFactoryBean factory = new HibernateJpaSessionFactoryBean();
         factory.setEntityManagerFactory(emf);
         return factory;
    }
}

That way you have both an EntityManagerFactory and a SessionFactory.

UPDATE: As of Hibernate 5 the SessionFactory actually extends the EntityManagerFactory. So to obtain a SessionFactory you can simply cast the EntityManagerFactory to it or use the unwrap method to get one.

public class SomeHibernateRepository {

  @PersistenceUnit
  private EntityManagerFactory emf;

  protected SessionFactory getSessionFactory() {
    return emf.unwrap(SessionFactory.class);
  }

}

Assuming you have a class with a main method with @EnableAutoConfiguration you don't need the @EnableTransactionManagement annotation, as that will be enabled by Spring Boot for you. A basic application class in the com.spring.app package should be enough.

@Configuration
@EnableAutoConfiguration
@ComponentScan
public class Application {


    public static void main(String[] args) throws Exception {
        SpringApplication.run(Application.class, args);
    }

} 

Something like that should be enough to have all your classes (including entities and Spring Data based repositories) detected.

UPDATE: These annotations can be replaced with a single @SpringBootApplication in more recent versions of Spring Boot.

@SpringBootApplication
public class Application {

    public static void main(String[] args) throws Exception {
        SpringApplication.run(Application.class, args);
    }
} 

I would also suggest removing the commons-dbcp dependency as that would allow Spring Boot to configure the faster and more robust HikariCP implementation.

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I was facing a similar problem when starting up the application (using Spring Boot) with the database server down.

Hibernate can determine the correct dialect to use automatically, but in order to do this, it needs a live connection to the database.

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add spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQLDialect in application.properties file

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I got this error when my database was not created. After creating the DB manually, it worked fine.

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I also faced a similar issue. But, it was due to the invalid password provided. Also, I would like to say your code seems to be old-style code using spring. You already mentioned that you are using spring boot, which means most of the things will be auto configured for you. hibernate dialect will be auto selected based on the DB driver available on the classpath along with valid credentials which can be used to test the connection properly. If there is any issue with the connection you will again face the same error. only 3 properties needed in application.properties

# Replace with your connection string
spring.datasource.url=jdbc:mysql://localhost:3306/pdb1

# Replace with your credentials
spring.datasource.username=root
spring.datasource.password=

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I ran into the same problem and my issue was that the DB I was trying to connect to didn't exist.

I created the DB, verified the URL/connection string and reran and everything worked as expected.

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Remove the redundant Hibernate Configuration

If you're using Spring Boot, you don't need to provide the JPA and Hibernate configuration explicitly, as Spring Boot can do that for you.

Add database configuration properties

In the application.properties Spring Boot configuration file, you have the add your database configuration properties:

spring.datasource.driverClassName = org.postgresql.Driver
spring.datasource.url = jdbc:postgresql://localhost:5432/teste
spring.datasource.username = klebermo
spring.datasource.password = 123

Add Hibernate specific properties

And, in the same application.properties configuration file, you can also set custom Hibernate properties:

# Log SQL statements
spring.jpa.show-sql = false

# Hibernate ddl auto for generating the database schema
spring.jpa.hibernate.ddl-auto = create

# Hibernate database Dialect
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.PostgreSQLDialect

That's it!

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I had same issue. adding this to the application.properties solved the issue:

spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQLDialect

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In spring boot for jpa java config you need to extend JpaBaseConfiguration and implement it's abstract methods.

@Configuration
public class JpaConfig extends JpaBaseConfiguration {

    @Override
    protected AbstractJpaVendorAdapter createJpaVendorAdapter() {
        final HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        return vendorAdapter;
    }

    @Override
    protected Map<String, Object> getVendorProperties() {
        Map<String, Object> properties = new HashMap<>();
        properties.put("hibernate.dialect", "org.hibernate.dialect.PostgreSQLDialect");
    }

}

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The following are some of the reasons for the hibernate.dialect not set issue. Most of these exceptions are shown in the startup log which is finally followed by the mentioned issue.

Example: In Spring boot app with Postgres DB

1. Check if the database is actually installed and its server is started.

org.postgresql.util.PSQLException: Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.

java.net.ConnectException: Connection refused: connect

org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]

2. Check if the database name is correctly mentioned.

org.postgresql.util.PSQLException: FATAL: database "foo" does not exist In application.properties file, spring.datasource.url = jdbc:postgresql://localhost:5432/foo but foo didn't exist. So I created the database from pgAdmin for postgres CREATE DATABASE foo;

3. Check if the host name and server port is accessible.

org.postgresql.util.PSQLException: Connection to localhost:5431 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.

java.net.ConnectException: Connection refused: connect

4. Check if the database credentials are correct.

as @Pankaj mentioned

org.postgresql.util.PSQLException: FATAL: password authentication failed for user "postgres" spring.datasource.username= {DB USERNAME HERE} spring.datasource.password= {DB PASSWORD HERE}

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this is happening because your code is not bale to connect the database. Make sure you have mysql driver and username, password correct.

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Make sure your application.properties has all correct info: (I changed my db port from 8889 to 3306 it worked)

 db.url: jdbc:mysql://localhost:3306/test

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It turns out there is no one mentioning set spring.jpa.database=mysql in application.properties file, if you use Spring JPA. This is the simplest answer to me and I want to share in this question.

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In my case the user could not connect to the database. If will have same issue if the log contains a warning just before the exception:

WARN HHH000342: Could not obtain connection to query metadata : Login failed for user 'my_user'.

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Make sure you have your database in your pom like OP did. That was my problem.

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My problem was that embedded database was already connected. close connection

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I got this issue when Eclipse was unable to find the JDBC driver. Had to do a gradle refresh from the eclipse to get this work.

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If you are using this line:

sessionFactory.getHibernateProperties().put("hibernate.dialect", env.getProperty("hibernate.dialect"));

make sure that env.getProperty("hibernate.dialect") is not null.

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Same but in a JBoss WildFly AS.

Solved with properties in my META-INF/persistence.xml

<properties>
            <property name="hibernate.transaction.jta.platform"
                value="org.hibernate.service.jta.platform.internal.JBossAppServerJtaPlatform" />
            <property name="spring.jpa.database-platform" value="org.hibernate.dialect.PostgreSQLDialect" />
            <property name="spring.jpa.show-sql" value="false" />
</properties>

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For those working with AWS MySQL RDS, it may occur when you are unable to connect to the database. Go to AWS Security Groups setting for MySQL RDS and edit the inbound IP rule by refreshing MyIP.

I faced this issue and doing above got the problem fixed for me.

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I also had this problem. In my case it was because of no grants were assigned to MySQL user. Assigning grants to MySQL user which my app uses resolved the issue:

grant select, insert, delete, update on my_db.* to 'my_user'@'%';

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I had the same issue and after debugging it turns out that Spring application.properties had wrong IP address for DB server

spring.datasource.url=jdbc:oracle:thin:@WRONG:1521/DEV

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Adding spring.jpa.database-platform=org.hibernate.dialect.MariaDB53Dialect to my properties file worked for me.

PS: i'm using MariaDB

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I reproduced this error message in the following three cases:

There does not exist database user with username written in application.properties file or persistence.properties file or, as in your case, in HibernateConfig file

The deployed database has that user but user is identified by different password than that in one of above files

The database has that user and the passwords match but that user does not have all privileges needed to accomplish all database tasks that your spring-boot app does

The obvious solution is to create new database user with the same username and password as in the spring-boot app or change username and password in your spring-boot app files to match an existing database user and grant sufficient privileges to that database user. In case of MySQL database this can be done as shown below:

mysql -u root -p 
>CREATE USER 'theuser'@'localhost' IDENTIFIED BY 'thepassword';
>GRANT ALL ON *.* to theuser@localhost IDENTIFIED BY 'thepassword';
>FLUSH PRIVILEGES;

Obviously there are similar commands in Postgresql but I haven't tested if in case of Postgresql this error message can be reproduced in these three cases.

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I had the same issue and it was caused by being unable to connect to the database instance. Look for hibernate error HHH000342 in the log above that error, it should give you an idea to where the db connection is failing (incorrect username/pass, url, etc.)

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This happened to me because I hadn't added the conf.configure(); before beginning the session:

Configuration conf = new Configuration();
conf.configure();

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Make sure that you have enter valid detail in application.properties and whether your database server is available. As a example when you are connecting with MySQL check whether XAMPP is running properly.

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I faced the same issue: The db I was trying to connect did not exist. I used jpa.database=default (which I guess means it will try to connect to the database and then auto select the dialect). Once I started the database, it worked fine without any change.

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I faced this issue due to Mysql 8.0.11 version reverting back to 5.7 solved for me

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I had the same error after using the hibernate code generation

https://www.mkyong.com/hibernate/how-to-generate-code-with-hibernate-tools/

then the hibernate.cfg.xml was created in /src/main/java but without the connection parameters after removing it - my problem was solved

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