def check_create_fk(self, from_table_id, to_table_id, ignoreexisting=False):
from_type = setobject_type_registry.lookup_by_table(from_table_id)
to_type = setobject_type_registry.lookup_by_table(to_table_id)
pk = to_type.get_primary_key_attr_name()
# Now add foreign key if not existant yet
if not field_exists(from_table_id, self.foreignkeycol):
col = Column(
self.foreignkeycol,
getattr(to_type.get_table_class().c, pk).type,
ForeignKey(to_table_id + "." + pk),
)
col.create(from_type.get_table_class())
# The foreign key column has been newly created
Session().flush()
# deferred import
from p2.datashackle.core.models.mapping import map_tables
map_tables(exclude_sys_tables=True)
else:
# it exists, check whether it is what we want or something else
fkset = getattr(from_type.get_table_class().c, self.foreignkeycol).foreign_keys
if len(fkset) > 0:
for fk in fkset:
if str(fk.column) == to_table_id + "." + pk \
and ignoreexisting == True:
return # this is what we want! fine.
raise UserException("A relation with a similar Data Field Name but targetting the table '" + \
str(fk.column).split('.',1)[0] + "' already exists. Please use another Data Field Name.")
raise UserException("The column '" + self.foreignkeycol + "' in the table '" + to_table_id + \
"' does already exist. Please choose a unique Data Field Name that doesn't collide with existing data columns.")
def map_field_attr(table_name, field_identifier, column_type):
assert(field_identifier != None)
if not field_exists(table_name, field_identifier):
# Create new Field
new_column = Column(field_identifier, column_type)
table = setobject_table_registry.lookup_by_table(table_name)
new_column.create(table)
# re-map setobject type
map_tables(exclude_sys_tables=True)
def _create_adjacency_list_relation(self):
if not field_exists(self.target_table, self.foreignkeycol):
target = setobject_type_registry.lookup_by_table(self.target_table)
pk = target.get_primary_key_attr_name()
col = Column(
self.foreignkeycol,
getattr(target.get_table_class().c, pk).type,
ForeignKey(self.target_table + "." + pk),
)
col.create(target.get_table_class())
# update session and remap table
#Session().flush()
# re-map user tables with newly created linkage
from p2.datashackle.core.models.mapping import map_tables
map_tables(exclude_sys_tables=True)
