ormar/docs/api/query-set/clause.md

queryset.clause

FilterGroup Objects

class FilterGroup()

Filter groups are used in complex queries condition to group and and or clauses in where condition

resolve

 | resolve(model_cls: Type["Model"], select_related: List = None, filter_clauses: List = None) -> Tuple[List[FilterAction], List[str]]

Resolves the FilterGroups actions to use proper target model, replace complex relation prefixes if needed and nested groups also resolved.

Arguments:

• model_cls (Type["Model"]): model from which the query is run
• select_related (List[str]): list of models to join
• filter_clauses (List[FilterAction]): list of filter conditions

Returns:

Tuple[List[FilterAction], List[str]]: list of filter conditions and select_related list

_iter

 | _iter() -> Generator

Iterates all actions in a tree

Returns:

Generator: generator yielding from own actions and nested groups

_get_text_clauses

 | _get_text_clauses() -> List[sqlalchemy.sql.expression.TextClause]

Helper to return list of text queries from actions and nested groups

Returns:

List[sqlalchemy.sql.elements.TextClause]: list of text queries from actions and nested groups

get_text_clause

 | get_text_clause() -> sqlalchemy.sql.expression.TextClause

Returns all own actions and nested groups conditions compiled and joined inside parentheses. Escapes characters if it's required. Substitutes values of the models if value is a ormar Model with its pk value. Compiles the clause.

Returns:

sqlalchemy.sql.elements.TextClause: complied and escaped clause

or_

or_(*args: FilterGroup, **kwargs: Any) -> FilterGroup

Construct or filter from nested groups and keyword arguments

Arguments:

• args (Tuple[FilterGroup]): nested filter groups
• kwargs (Any): fields names and proper value types

Returns:

ormar.queryset.clause.FilterGroup: FilterGroup ready to be resolved

and_

and_(*args: FilterGroup, **kwargs: Any) -> FilterGroup

Construct and filter from nested groups and keyword arguments

Arguments:

• args (Tuple[FilterGroup]): nested filter groups
• kwargs (Any): fields names and proper value types

Returns:

ormar.queryset.clause.FilterGroup: FilterGroup ready to be resolved

QueryClause Objects

class QueryClause()

Constructs FilterActions from strings passed as arguments

prepare_filter

 | prepare_filter(_own_only: bool = False, **kwargs: Any) -> Tuple[List[FilterAction], List[str]]

Main external access point that processes the clauses into sqlalchemy text clauses and updates select_related list with implicit related tables mentioned in select_related strings but not included in select_related.

Arguments:

• _own_only:
• kwargs (Any): key, value pair with column names and values

Returns:

Tuple[List[sqlalchemy.sql.elements.TextClause], List[str]]: Tuple with list of where clauses and updated select_related list

_populate_filter_clauses

 | _populate_filter_clauses(_own_only: bool, **kwargs: Any) -> Tuple[List[FilterAction], List[str]]

Iterates all clauses and extracts used operator and field from related models if needed. Based on the chain of related names the target table is determined and the final clause is escaped if needed and compiled.

Arguments:

• kwargs (Any): key, value pair with column names and values

Returns:

Tuple[List[sqlalchemy.sql.elements.TextClause], List[str]]: Tuple with list of where clauses and updated select_related list

_register_complex_duplicates

 | _register_complex_duplicates(select_related: List[str]) -> None

Checks if duplicate aliases are presented which can happen in self relation or when two joins end with the same pair of models.

If there are duplicates, the all duplicated joins are registered as source model and whole relation key (not just last relation name).

Arguments:

• select_related (List[str]): list of relation strings

Returns:

None: None

_parse_related_prefixes

 | _parse_related_prefixes(select_related: List[str]) -> List[Prefix]

Walks all relation strings and parses the target models and prefixes.

Arguments:

• select_related (List[str]): list of relation strings

Returns:

List[Prefix]: list of parsed prefixes

_switch_filter_action_prefixes

 | _switch_filter_action_prefixes(filter_clauses: List[FilterAction]) -> List[FilterAction]

Substitutes aliases for filter action if the complex key (whole relation str) is present in alias_manager.

Arguments:

• filter_clauses (List[FilterAction]): raw list of actions

Returns:

List[FilterAction]: list of actions with aliases changed if needed

_verify_prefix_and_switch

 | _verify_prefix_and_switch(action: "FilterAction") -> None

Helper to switch prefix to complex relation one if required

Arguments:

• action (ormar.queryset.actions.filter_action.FilterAction): action to switch prefix in