SearchRank

This class represents a database function that calculates the relevance score of a search vector against a search query. It supports optional weighting, normalization, and cover density ranking by switching between the underlying ts_rank and ts_rank_cd functions. The class ensures that input vectors and queries are properly resolved and cast to the appropriate database types for execution.

Attributes

Attribute	Type	Description
function	string = ts_rank	The name of the database function used to calculate the search rank, which defaults to 'ts_rank' but changes to 'ts_rank_cd' if cover_density is enabled.
output_field	[FloatField](../../../forms/fields/floatfield.md?sid=django_forms_fields_floatfield)	The database field type used to represent the calculated rank value, which is a FloatField.

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Constructor

Signature

def SearchRank(
    vector: SearchVector | Expression,
    query: SearchQuery | Expression,
    weights: list | Expression = None,
    normalization: int | Expression = None,
    cover_density: boolean = False
) - > null

Parameters

Name	Type	Description
vector	`SearchVector	Expression`
query	`SearchQuery	Expression`
weights	`list	Expression` = None
normalization	`int	Expression` = None
cover_density	boolean = False	If True, uses the ts_rank_cd function which considers the proximity of matching lexemes.

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Signature

def SearchRank(
    vector: SearchVector | str,
    query: SearchQuery | str,
    weights: list | Value | None = None,
    normalization: int | Value | None = None,
    cover_density: bool = False
)

Parameters

Name	Type	Description
vector	`SearchVector	str`
query	`SearchQuery	str`
weights	`list	Value
normalization	`int	Value
cover_density	bool = False	When True, switches the underlying function to 'ts_rank_cd' which accounts for the proximity of matching lexemes.

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