==================================
How to migrate to another database
==================================

You can migrate your data to another database.

For example, you developed your project with SQLite database and want to move to 
Postgress.

To do this, follow these steps:

#. Create an empty Postgress database

#. Create a new project with this database

#. Export the metadata of the SQLite project to a zip file 
   in the Application Builder by clicking the 
   :doc:`Export </admin/project/export>` button.

#. Import the metadata to the new project. The web application with create
   database structures in the Postgress database.
  
#. copy data from SQlite to Postgress database using the 
   :doc:`copy_database </refs/server/task/m_copy_database>` method of the task:
  
   * within the Project\Task create the following Server Module function (adjust the below database path with correct one):
  
     .. code-block:: py
    
       from jam.db.db_modules import SQLITE
      
       def copy_db(task):
           task.copy_database(SQLITE, '/home/work/demo/demo.sqlite')
  
   * then, execute it with the one of the following ways:
  
     * call this function in the 
       :doc:`on_created </refs/server/task/on_created>` event handler:

       .. code-block:: py
      
         from jam.db.db_modules import SQLITE
        
         def copy_db(task):
             task.copy_database(SQLITE, '/home/work/demo/demo.sqlite')
 
         def on_created(task):
           copy_db(task)
          
     * create a button in some form and use the task 
       :doc:`server </refs/client/abstr_item/m_server>` method to execute it

       .. code-block:: js

         function on_view_form_created(item) {
           item.add_view_button('Copy DB').click(function() { 
             task.server('copy_db')
           });
         }

     * or run from from debugging console of the browser:
    
       .. code-block:: js

         task.server('copy_db')
         
#. Remove the code that was used immediately after this procedure.         

.. note::
	
	You can not migrate to SQLite database if the current database has foreign
	keys.