Package orm2 :: Module relationships :: Class one2many

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Class one2many

    object --+                
             |                
      property --+            
                 |            
datatypes.datatype --+        
                     |        
          relationship --+    
                         |    
                    _2many --+
                             |
                            one2many

A one2many relationship is probably the most common relationship between two tables in a RDBMS. For each row in table A table B contains zero or more rows. This is implemented by defining a column in table B that contains values that uniquly specify the row in table A they belong to. This is called a 'foreign key', i.e. a key that belongs to a foreign table.

Nested Classes

result

Instance Methods

__init_dbclass__(self, dbclass, attribute_name)
This methods gets called by dbobject's metaclass.

__set__(self, dbobj, value)
Setting a one2many relationship needs three steps:

Inherited from _2many: __get__

Inherited from relationship: __convert__, __init__, __select_after_insert__, __select_this_column__, __set_from_result__, isset, sql_literal

Inherited from datatypes.datatype: __delete__, __setattr__, add_widget, check_dbobj, data_attribute_name, widget_specs

Inherited from property: __getattribute__, __new__

Inherited from object: __delattr__, __hash__, __reduce__, __reduce_ex__, __repr__, __str__

Class Variables

Inherited from datatypes.datatype: python_class, sql_literal_class

Inherited from property: fdel, fget, fset

Properties

Inherited from object: __class__

Method Details

__init_dbclass__(self, dbclass, attribute_name)

This methods gets called by dbobject's metaclass. It supplies the db property with info about the class it belongs to and its attribute name.

Overrides: _2many.__init_dbclass__

set(self, dbobj, value)

Setting a one2many relationship needs three steps:

value must be a list of new (not-yet inserted) child objects
delete all child objects from the db
insert all child objects on the list with the foreign key pointing to dbobj

Overrides: _2many.__set__