Changing the connection string at runtime

graphicsxp · **Joined:** Thu Aug 14, 2008 5:31 pm **Posts:** 20

Hi,

My config file is as followed :

Code:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-configuration xmlns="urn:nhibernate-configuration-2.2" >
  <session-factory>
    <property name="connection.provider">NHibernate.Connection.DriverConnectionProvider</property>
    <property name="connection.driver_class">NHibernate.Driver.SqlClientDriver</property>
    <property name="connection.connection_string">MyConnectionString</property>
    <property name="show_sql">true</property>
    <property name="dialect">NHibernate.Dialect.MsSql2005Dialect</property>
    <mapping assembly="DataTransfer"/>
  </session-factory>
</hibernate-configuration>

Now I'm trying to change the connection string at runtime. I do it as followed :

Code:

 private static ISession GetSession()
    {      
      Configuration cfg = new Configuration();
      cfg.SetProperty("hibernate.connection.connection_string", "AnotherConnectionString");
      
      ISessionFactory sessionFactory = cfg.BuildSessionFactory();
      cfg.Configure();
      ISession session = sessionFactory.OpenSession();
      
      return session;
    }

Once I called cfg.Configure(), the property "hibernate.connection.connection_string" is reset to what it was in the config file. So how can I force nhibernate to use the new connection string that I pass to the Configuration object in my code ?

Is there something I'm doing wrong ?

graphicsxp · **Joined:** Thu Aug 14, 2008 5:31 pm **Posts:** 20

duplicate message. sorry.

graphicsxp · **Joined:** Thu Aug 14, 2008 5:31 pm **Posts:** 20

Anyone has an idea about this ? It must be something lot of people do all the time ! I really need to find a solution urgently.

wolli · **Posted:** Wed Sep 24, 2008 2:43 am

Quote:

Configure NHibernate using the <hibernate-configuration> section from the application config file, if found, or the file hibernate.cfg.xml otherwise.

Configure() actually (re-)reads the settings from the file. I think that's already done with "new Configuration()". Try without the explicit call.

graphicsxp · **Joined:** Thu Aug 14, 2008 5:31 pm **Posts:** 20

Thanks for helping ! I'm really getting frustrated with this.

Are you suggesting I should not call cfg.Configure(); ?

I've tried that but I get the following exception :

Quote:

The hibernate.connection.driver_class must be specified in the NHibernate configuration section.

So I've tried to redefine all the properties in the code as such :

Code:

 cfg.SetProperty("connection.provider", "NHibernate.Connection.DriverConnectionProvider");
        cfg.SetProperty("connection.driver_class", "NHibernate.Driver.SqlClientDriver");
        cfg.SetProperty("dialect", "NHibernate.Dialect.MsSql2005Dialect");
        cfg.SetProperty("hibernate.connection.connection_string", _cnnMgr.GetConnectionString("anotherConnectionString");
        cfg.SetProperty("connection.connection_string", _cnnMgr.GetConnectionString("anotherConnectionString");

But I'm still getting the same error...

I can't understand why SetProperty just doesnt do the job, as it should be its purpose to change a property at runtime (in my case the connection string)

wolli · **Posted:** Wed Sep 24, 2008 4:53 am

Which NHibernate version do you use ? Is your hibernate config in App.config or hibernate.cfg.xml ?

graphicsxp · **Joined:** Thu Aug 14, 2008 5:31 pm **Posts:** 20

I use version 1.2.1.4000

My config is in hibernate.cfg.xml.

Does this help ?

graphicsxp · **Joined:** Thu Aug 14, 2008 5:31 pm **Posts:** 20

I use version 1.2.1.4000

My config is in hibernate.cfg.xml.

Does this help ?

wolli · **Posted:** Wed Sep 24, 2008 5:05 am

I just checked the docs. Seems that you don't need Configure() when you use App.config. With hibernate.cfg.xml you need it. Have you tried setting the property first ?

Code:

Configuration cfg = new Configuration();
cfg.SetProperty(...);
ISessionFactory sessionFactory = cfg.Configure().BuildSessionFactory(); 

graphicsxp · **Joined:** Thu Aug 14, 2008 5:31 pm **Posts:** 20

If I do it as you say, I got no exception raised.

After cfg.SetProperty is called, the connection string in cfg is the one I'm setting in the code, which is what I want.

However as soon as cfg.Configure().BuildSessionFactory() is called, the connection string is reset to the one in the hbiernate.cfg.xml file.

This is crazy... :(

wolli · **Posted:** Wed Sep 24, 2008 6:40 am

Oops, sorry, my example isn't doing what I was talking about. I meant you should try and call Configure() and then set the connection string.

Code:

Configuration cfg = new Configuration();
cfg.Configure().SetProperty(...);
ISessionFactory sessionFactory = cfg.BuildSessionFactory();

graphicsxp · **Joined:** Thu Aug 14, 2008 5:31 pm **Posts:** 20

Yes ! That seems to have done the trick !

Thanks a lot for your help, much appreciated.

Actually would you mind taking a quick look at my other issue (http://forum.hibernate.org/viewtopic.php?t=990735), maybe you know the answer...

cheers

reflection · **Joined:** Wed Feb 11, 2009 10:58 am **Posts:** 55

thanks needed that, too :)