Class BaseQuery (2.9.0)

BaseQuery(
    parent,
    projection=None,
    field_filters=(),
    orders=(),
    limit=None,
    limit_to_last=False,
    offset=None,
    start_at=None,
    end_at=None,
    all_descendants=False,
    recursive=False,
)

Represents a query to the Firestore API.

Instances of this class are considered immutable: all methods that would modify an instance instead return a new instance.

Parameters

Name	Description
`parent`	`CollectionReference` The collection that this query applies to.
`projection`	`Optional[Projection]` A projection of document fields to limit the query results to.
`field_filters`	`Optional[Tuple[FieldFilter, ...]]` The filters to be applied in the query.
`orders`	`Optional[Tuple[Order, ...]]` The "order by" entries to use in the query.
`limit`	`Optional[int]` The maximum number of documents the query is allowed to return.
`limit_to_last`	`Optional[bool]` Denotes whether a provided limit is applied to the end of the result set.
`offset`	`Optional[int]` The number of results to skip.
`start_at`	`Optional[Tuple[dict, bool]]` Two-tuple of : * a mapping of fields. Any field that is present in this mapping must also be present in `orders` * an `after` flag The fields and the flag combine to form a cursor used as a starting point in a query result set. If the `after` flag is :data:`True`, the results will start just after any documents which have fields matching the cursor, otherwise any matching documents will be included in the result set. When the query is formed, the document values will be used in the order given by `orders`.
`end_at`	`Optional[Tuple[dict, bool]]` Two-tuple of: * a mapping of fields. Any field that is present in this mapping must also be present in `orders` * a `before` flag The fields and the flag combine to form a cursor used as an ending point in a query result set. If the `before` flag is :data:`True`, the results will end just before any documents which have fields matching the cursor, otherwise any matching documents will be included in the result set. When the query is formed, the document values will be used in the order given by `orders`.
`all_descendants`	`Optional[bool]` When false, selects only collections that are immediate children of the `parent` specified in the containing `RunQueryRequest`. When true, selects all descendant collections.
`recursive`	`Optional[bool]` When true, returns all documents and all documents in any subcollections below them. Defaults to false.

Methods

end_at

end_at(
    document_fields_or_snapshot: Union[
        google.cloud.firestore_v1.base_document.DocumentSnapshot, dict, list, tuple
    ]
)

End query results at a particular document value.

The result set will include the document specified by document_fields_or_snapshot.

If the current query already has specified an end cursor -- either via this method or xref_end_before -- this will overwrite it.

When the query is sent to the server, the document_fields_or_snapshot will be used in the order given by fields set by xref_order_by.

Returns

Type	Description
`Query`	A query with cursor. Acts as a copy of the current query, modified with the newly added "end at" cursor.

end_before

end_before(
    document_fields_or_snapshot: Union[
        google.cloud.firestore_v1.base_document.DocumentSnapshot, dict, list, tuple
    ]
)

End query results before a particular document value.

The result set will exclude the document specified by document_fields_or_snapshot.

If the current query already has specified an end cursor -- either via this method or xref_end_at -- this will overwrite it.

When the query is sent to the server, the document_fields_or_snapshot will be used in the order given by fields set by xref_order_by.

Returns

Type	Description
`Query`	A query with cursor. Acts as a copy of the current query, modified with the newly added "end before" cursor.

limit

limit(count: int)

Limit a query to return at most count matching results.

If the current query already has a limit set, this will override it.

Note: limit and limit_to_last are mutually exclusive. Setting limit will drop previously set limit_to_last.

Parameter

Name	Description
`count`	`int` Maximum number of documents to return that match the query.

Returns

Type	Description
`Query`	A limited query. Acts as a copy of the current query, modified with the newly added "limit" filter.

limit_to_last

limit_to_last(count: int)

Limit a query to return the last count matching results. If the current query already has a limit_to_last set, this will override it.

Note: limit and limit_to_last are mutually exclusive. Setting limit_to_last will drop previously set limit.

Parameter

Name	Description
`count`	`int` Maximum number of documents to return that match the query.

Returns

Type	Description
`Query`	A limited query. Acts as a copy of the current query, modified with the newly added "limit" filter.

offset

offset(num_to_skip: int)

Skip to an offset in a query.

If the current query already has specified an offset, this will overwrite it.

Parameter

Name	Description
`num_to_skip`	`int` The number of results to skip at the beginning of query results. (Must be non-negative.)

Returns

Type	Description
`Query`	An offset query. Acts as a copy of the current query, modified with the newly added "offset" field.

order_by

order_by(field_path: str, direction: str = "ASCENDING")

Modify the query to add an order clause on a specific field.

See xref_field_path for more information on field paths.

Successive xref_order_by calls will further refine the ordering of results returned by the query (i.e. the new "order by" fields will be added to existing ones).

Parameters

Name	Description
`field_path`	`str` A field path (`.`-delimited list of field names) on which to order the query results.
`direction`	`Optional[str]` The direction to order by. Must be one of `ASCENDING` or `DESCENDING`, defaults to `ASCENDING`.

Exceptions

Type	Description
`ValueError`	If `field_path` is invalid.
`ValueError`	If `direction` is not one of `ASCENDING` or `DESCENDING`.

Returns

Type	Description
`Query`	An ordered query. Acts as a copy of the current query, modified with the newly added "order by" constraint.

recursive

recursive()

Returns a copy of this query whose iterator will yield all matching documents as well as each of their descendent subcollections and documents.

This differs from the all_descendents flag, which only returns descendents whose subcollection names match the parent collection's name. To return all descendents, regardless of their subcollection name, use this.

select

select(field_paths: Iterable[str])

Project documents matching query to a limited set of fields.

See xref_field_path for more information on field paths.

If the current query already has a projection set (i.e. has already called xref_select), this will overwrite it.

Parameter

Name	Description
`field_paths`	`Iterable[str, ...]` An iterable of field paths (`.`-delimited list of field names) to use as a projection of document fields in the query results.

Exceptions

Type	Description
`ValueError`	If any `field_path` is invalid.

Returns

Type	Description
`Query`	A "projected" query. Acts as a copy of the current query, modified with the newly added projection.

start_after

start_after(
    document_fields_or_snapshot: Union[
        google.cloud.firestore_v1.base_document.DocumentSnapshot, dict, list, tuple
    ]
)

Start query results after a particular document value.

The result set will exclude the document specified by document_fields_or_snapshot.

If the current query already has specified a start cursor -- either via this method or xref_start_at -- this will overwrite it.

When the query is sent to the server, the document_fields_or_snapshot will be used in the order given by fields set by xref_order_by.

Returns

Type	Description
`Query`	A query with cursor. Acts as a copy of the current query, modified with the newly added "start after" cursor.

start_at

start_at(
    document_fields_or_snapshot: Union[
        google.cloud.firestore_v1.base_document.DocumentSnapshot, dict, list, tuple
    ]
)

Start query results at a particular document value.

The result set will include the document specified by document_fields_or_snapshot.

If the current query already has specified a start cursor -- either via this method or xref_start_after -- this will overwrite it.

When the query is sent to the server, the document_fields will be used in the order given by fields set by xref_order_by.

Returns

Type	Description
`Query`	A query with cursor. Acts as a copy of the current query, modified with the newly added "start at" cursor.

where

where(field_path: str, op_string: str, value)

Filter the query on a field.

See xref_field_path for more information on field paths.

Returns a new xref_Query that filters on a specific field path, according to an operation (e.g. == or "equals") and a particular value to be paired with that operation.

Parameters

Name	Description
`field_path`	`str` A field path (`.`-delimited list of field names) for the field to filter on.
`op_string`	`str` A comparison operation in the form of a string. Acceptable values are `<`, `<=`, `==`, `!=`, `>=`, `>`, `in`, `not-in`, `array_contains` and `array_contains_any`.
`value`	`Any` The value to compare the field against in the filter. If `value` is :data:`None` or a NaN, then `==` is the only allowed operation.

Exceptions

Type	Description
`ValueError`	If `field_path` is invalid.
`ValueError`	If `value` is a NaN or :data:`None` and `op_string` is not `==`.

Returns

Type	Description
`Query`	A filtered query. Acts as a copy of the current query, modified with the newly added filter.