SessionFactory sf=config.configure().buildSessionFactory(); Session session=sf.openSession();

Use the mappings and properties specified in an application resource named hibernate.cfg.xml

configure()方法默认加载hibernate.cfg.xml文件，使该文件的映射和配置在应用程序中使用；configure()还有重载的方法来指定配置分别是

　　

若使用configure方法那么就可以在hibernate.cfg.xml中配置数据库的dialect：

      

通过配置来指定数据库对于的的dialect，具体的数据库和数据库对于的dialect如下：

 

使用spring和hibernate时如果使用时，有时候会去掉hibernate.cfg.xml，那么则要在Spring中配置dialect

　　

通过Hibernate Reference 可以知道，Dialect这部分内容使和数据库的移植性有相关的，在3.2之前的版本，Hibernate是要求用户明确指定数据库的Dialect的，3.2或以上版本通过java.sql.DataBaseMetaData来确定数据库；不过该文档同时指出来这种方法局限于Hibernate已知的数据库且无法进行配置和覆盖。3.3以后，用户可以通过重写org.hibernate.resolver.DialectResolver的resolveDialect方法来自定义方言，“要注册一个或多个解析者，只要用 'hibernate.dialect_resolvers' 配置设置指定它们（由逗号、制表符或空格隔开）就可以了（请参考 org.hibernate.cfg.Environment 上的 DIALECT_RESOLVERS）”。

用户定义的类通过AvailableSettings.DIALECT_RESOLVERS 获取类名，然后通过反射来注册DialectResolver。AvailableSettings.DIALECT_RESOLVERS 配置的类在determineResolvers链上先于StandardDialectResolver，所以自定义的解释者更优先处理DatabaseMetaData。

以下使hibernate初始化DialectResolver链的类。

import org.hibernate.HibernateException;
import org.hibernate.cfg.AvailableSettings;
import org.hibernate.internal.util.StringHelper;
import org.hibernate.service.classloading.spi.ClassLoaderService;
import org.hibernate.service.spi.ServiceException;
import org.hibernate.service.spi.ServiceRegistryImplementor;
import org.hibernate.service.jdbc.dialect.spi.DialectResolver;
import org.hibernate.service.spi.BasicServiceInitiator;/**
* Standard initiator for the standard {@link DialectResolver} service
*
* @author Steve Ebersole
*/
public class DialectResolverInitiator implements BasicServiceInitiator<DialectResolver> {public static final DialectResolverInitiator INSTANCE = new DialectResolverInitiator();@Overridepublic Class<DialectResolver> getServiceInitiated() {return DialectResolver.class;}@Overridepublic DialectResolver initiateService(Map configurationValues, ServiceRegistryImplementor registry) {return new DialectResolverSet( determineResolvers( configurationValues, registry ) );}private List<DialectResolver> determineResolvers(Map configurationValues, ServiceRegistryImplementor registry) {final List<DialectResolver> resolvers = new ArrayList
();final String resolverImplNames = (String) configurationValues.get( AvailableSettings.DIALECT_RESOLVERS );if ( StringHelper.isNotEmpty( resolverImplNames ) ) {final ClassLoaderService classLoaderService = registry.getService( ClassLoaderService.class );for ( String resolverImplName : StringHelper.split( ", \n\r\f\t", resolverImplNames ) ) {try {resolvers.add( (DialectResolver) classLoaderService.classForName( resolverImplName ).newInstance() );}catch (HibernateException e) {throw e;}catch (Exception e) {throw new ServiceException( "Unable to instantiate named dialect resolver [" + resolverImplName + "]", e );}}}resolvers.add( new StandardDialectResolver() );return resolvers;}
}