working for simple models, not including related models yet

This commit is contained in:
collerek
2020-11-08 09:44:30 +01:00
parent 8e2a368203
commit 9f4bde595f
3 changed files with 154 additions and 3 deletions

View File

@ -21,6 +21,7 @@ class Query:
limit_count: Optional[int],
offset: Optional[int],
fields: Optional[List],
order_bys: Optional[List],
) -> None:
self.query_offset = offset
self.limit_count = limit_count
@ -36,6 +37,7 @@ class Query:
self.select_from: List[str] = []
self.columns = [sqlalchemy.Column]
self.order_columns = order_bys
self.order_bys: List[sqlalchemy.sql.elements.TextClause] = []
@property
@ -43,6 +45,15 @@ class Query:
pkname_alias = self.model_cls.get_column_alias(self.model_cls.Meta.pkname)
return f"{self.table.name}.{pkname_alias}"
def apply_order_bys_for_primary_model(self):
if self.order_columns:
return [
text(f"{x[1:]} desc") if x.startswith("-") else text(x)
for x in self.order_columns
if "__" not in x
]
return [text(self.prefixed_pk_name)]
def build_select_expression(self) -> Tuple[sqlalchemy.sql.select, List[str]]:
self_related_fields = self.model_cls.own_table_columns(
self.model_cls, self.fields
@ -50,7 +61,7 @@ class Query:
self.columns = self.model_cls.Meta.alias_manager.prefixed_columns(
"", self.table, self_related_fields
)
self.order_bys = [text(self.prefixed_pk_name)]
self.order_bys = self.apply_order_bys_for_primary_model()
self.select_from = self.table
self._select_related.sort(key=lambda item: (item, -len(item)))

View File

@ -27,6 +27,7 @@ class QuerySet:
limit_count: int = None,
offset: int = None,
columns: List = None,
order_bys: List = None,
) -> None:
self.model_cls = model_cls
self.filter_clauses = [] if filter_clauses is None else filter_clauses
@ -35,7 +36,7 @@ class QuerySet:
self.limit_count = limit_count
self.query_offset = offset
self._columns = columns or []
self.order_bys = None
self.order_bys = order_bys or []
def __get__(
self,
@ -110,9 +111,10 @@ class QuerySet:
offset=self.query_offset,
limit_count=self.limit_count,
fields=self._columns,
order_bys=self.order_bys,
)
exp = qry.build_select_expression()
# print(exp.compile(compile_kwargs={"literal_binds": True}))
print(exp.compile(compile_kwargs={"literal_binds": True}))
return exp
def filter(self, _exclude: bool = False, **kwargs: Any) -> "QuerySet": # noqa: A003
@ -137,6 +139,7 @@ class QuerySet:
limit_count=self.limit_count,
offset=self.query_offset,
columns=self._columns,
order_bys=self.order_bys,
)
def exclude(self, **kwargs: Any) -> "QuerySet": # noqa: A003
@ -155,6 +158,7 @@ class QuerySet:
limit_count=self.limit_count,
offset=self.query_offset,
columns=self._columns,
order_bys=self.order_bys,
)
def fields(self, columns: Union[List, str]) -> "QuerySet":
@ -170,6 +174,23 @@ class QuerySet:
limit_count=self.limit_count,
offset=self.query_offset,
columns=columns,
order_bys=self.order_bys,
)
def order_by(self, columns: Union[List, str]) -> "QuerySet":
if not isinstance(columns, list):
columns = [columns]
order_bys = self.order_bys + [x for x in columns if x not in self.order_bys]
return self.__class__(
model_cls=self.model,
filter_clauses=self.filter_clauses,
exclude_clauses=self.exclude_clauses,
select_related=self._select_related,
limit_count=self.limit_count,
offset=self.query_offset,
columns=self._columns,
order_bys=order_bys,
)
async def exists(self) -> bool:
@ -218,6 +239,7 @@ class QuerySet:
limit_count=limit_count,
offset=self.query_offset,
columns=self._columns,
order_bys=self.order_bys,
)
def offset(self, offset: int) -> "QuerySet":
@ -229,6 +251,7 @@ class QuerySet:
limit_count=self.limit_count,
offset=offset,
columns=self._columns,
order_bys=self.order_bys,
)
async def first(self, **kwargs: Any) -> "Model":