'hibernate.dialect' must be set when no Connection available error

Question

I am getting the following error when using Hibernate:

\'hibernate.dialect\' must be set when no Connection available

And I am using a datasource fo

Answer 1

The issue could be that you haven't installed the client library for the database you are trying to connect to.

I have a Spring application that does not have a persistence.xml file and therefore no hibernate.dialect declaration.

Once I installed the MySQL Connector/J client library the error went away.

EDIT: I've also gotten this error when the database server wasn't running. Something that often happens now that I run my MySQL server through MAMP.

Answer 2

You need to set the property

hibernate.dialect

In the hibernate (persistence.xml or bean declaration) configuration, the value depends on your database, for example:

Postgres: org.hibernate.dialect.PostgreSQL82Dialect
Oracle: org.hibernate.dialect.Oracle10gDialect

All posible options are listen here

For example, a sample persistence.xml looks like:

<persistence-unit>
    ...
    <properties>
        ...
        <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect" />
        ...
    </properties>
</persistence-unit>

Answer 3

Just encountered this issue. In my case it was the hibernate.dialect configuration.I added the following to SessionFatcory config in spring context file:

<bean id="mySessionFactory"
    class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
    <property name="annotatedClasses">
        <list>
            <value>com.testapp.service.geolocation.LocationData</value>
            <value>com.testapp.service.profiles.Profile</value>
        </list>
    </property>    
     <property name="hibernateProperties">
        <value>hibernate.dialect=org.hibernate.dialect.HSQLDialect</value>
    </property>
 </bean>

Answer 4

In the Hibernate configuration dialog has a tab "options" it is possible to select some. In this case I was using Oracle Enterprise Pack for Eclipse that already had configured connector, but was still getting the error. Select an option on the list was enough to solve.

Answer 5

You will get this issue even if you have your configuration files having proper value but you don't configure it in the code.

I was explaining hibernate, I forgot to use configure() before buildSessionFactory() so I was getting the error.

You might want to recheck it.

Previous code which was giving me error

SessionFactory factory = new Configuration().buildSessionFactory();

Changed code No Error

SessionFactory factory = new Configuration().configure().buildSessionFactory();

Answer 6

This error is hibernate doing a poor job of telling you what went wrong with your attempted connection with database.

In my case it was as simple as having a wrong password in config file.