def join_to_table(
table,
table2,
table_field,
table2_field,
queryset,
alias,
extra_restriction_func=lambda where_class, alias, related_alias: None):
"""
Add a join on `table2` to `queryset` (having table `table`).
"""
foreign_object = ForeignObject(to=table2,
from_fields=[None],
to_fields=[None],
rel=None)
foreign_object.opts = Options(table._meta)
foreign_object.opts.model = table
foreign_object.get_joining_columns = lambda: (
(table_field, table2_field), )
foreign_object.get_extra_restriction = extra_restriction_func
join = Join(table2._meta.db_table, table._meta.db_table, alias, LOUTER,
foreign_object, True)
queryset.query.join(join)
# hook for set alias
join.table_alias = alias
queryset.query.external_aliases.add(alias)
return queryset
def join_to(queryset, subquery, table_field, subquery_field, alias, join_type,
nullable):
"""
Add a join on `subquery` to `queryset` (having table `table`).
"""
# here you can set complex clause for join
def extra_join_cond(where_class, alias, related_alias):
if (alias, related_alias) == ('[sys].[columns]',
'[sys].[database_permissions]'):
where = '[sys].[columns].[column_id] = ' \
'[sys].[database_permissions].[minor_id]'
children = [ExtraWhere([where], ())]
return where_class(children)
return None
table = queryset.model
foreign_object = ForeignObject(to=subquery,
on_delete=DO_NOTHING,
from_fields=[None],
to_fields=[None],
rel=None)
foreign_object.opts = Options(table._meta)
foreign_object.opts.model = table
foreign_object.get_joining_columns = lambda: (
(table_field, subquery_field), )
foreign_object.get_extra_restriction = extra_join_cond
if isinstance(subquery.query, RawQuery):
subquery_sql, subquery_params = subquery.query.sql, subquery.query.params
else:
subquery_sql, subquery_params = subquery.query.sql_with_params()
join = CustomJoin(subquery_sql, subquery_params, table._meta.db_table,
alias, join_type, foreign_object, nullable)
# init first alias for this query
queryset.query.get_initial_alias()
# join subquery
queryset.query.join(join)
# hook for set alias
join.table_alias = alias
return queryset
def join_to(table, subquery, table_field, subquery_field, queryset, alias):
"""
Add a join on `subquery` to `queryset` (having table `table`).
"""
# here you can set complex clause for join
def extra_join_cond(where_class, alias, related_alias):
if (alias, related_alias) == ('[sys].[columns]',
'[sys].[database_permissions]'):
where = '[sys].[columns].[column_id] = ' \
'[sys].[database_permissions].[minor_id]'
children = [ExtraWhere([where], ())]
return where_class(children)
return None
foreign_object = ForeignObject(to=subquery,
from_fields=[None],
to_fields=[None],
rel=None,
on_delete=models.DO_NOTHING)
foreign_object.opts = Options(table._meta)
foreign_object.opts.model = table
foreign_object.get_joining_columns = lambda: (
(table_field, subquery_field), )
foreign_object.get_extra_restriction = extra_join_cond
subquery_sql, subquery_params = subquery.query.sql_with_params()
join = CustomJoin(subquery_sql, subquery_params, table._meta.db_table,
alias, "LEFT JOIN", foreign_object, True)
queryset.query.join(join)
# hook for set alias
join.table_alias = alias
queryset.query.external_aliases.add(alias)
return queryset
def join_to_queryset(
table,
subquery,
table_field,
subquery_field,
queryset,
alias,
is_raw=False,
extra_restriction_func=lambda where_class, alias, related_alias: None):
"""
Add a join on `subquery` to `queryset` (having table `table`).
"""
foreign_object = ForeignObject(to=subquery,
from_fields=[None],
to_fields=[None],
rel=None,
on_delete=models.CASCADE)
foreign_object.opts = Options(table._meta)
foreign_object.opts.model = table
foreign_object.get_joining_columns = lambda: (
(table_field, subquery_field), )
foreign_object.get_extra_restriction = extra_restriction_func
subquery_sql, subquery_params = (
subquery.query, []) if is_raw else subquery.query.sql_with_params()
join = CustomJoin(subquery_sql, subquery_params, table._meta.db_table,
alias, LOUTER, foreign_object, True)
queryset.query.join(join)
# hook for set alias
join.table_alias = alias
queryset.query.external_aliases.add(alias)
return queryset