Class SortedSetSortField

SortField for Lucene.Net.Index.SortedSetDocValues.

A Lucene.Net.Index.SortedSetDocValues contains multiple values for a field, so sorting with this technique "selects" a value as the representative sort value for the document.

By default, the minimum value in the set is selected as the sort value, but this can be customized. Selectors other than the default do have some limitations (see below) to ensure that all selections happen in constant-time for performance.

Like sorting by string, this also supports sorting missing values as first or last, via SetMissingValue(object).

Limitations:
  • Fields containing MaxValue or more unique values are unsupported.
  • Selectors other than the default MIN require optional codec support. However several codecs provided by Lucene, including the current default codec, support this.
Inheritance
object
SortField
SortedSetSortField
Inherited Members
SortField.FIELD_SCORE
SortField.FIELD_DOC
SortField.MissingValue
SortField.m_missingValue
SortField.STRING_FIRST
SortField.STRING_LAST
SortField.Field
SortField.Type
SortField.Parser
SortField.IsReverse
SortField.ComparerSource
SortField.BytesComparer
SortField.Rewrite(IndexSearcher)
SortField.NeedsScores
Namespace: Lucene.Net.Sandbox.Queries
Assembly: Lucene.Net.Sandbox.dll
Syntax
public class SortedSetSortField : SortField

Constructors

SortedSetSortField(string, bool)

Creates a sort, possibly in reverse, by the minimum value in the set for the document.

Declaration
public SortedSetSortField(string field, bool reverse)
Parameters
Type Name Description
string field

Name of field to sort by. Must not be null.
bool reverse

True if natural order should be reversed.

SortedSetSortField(string, bool, Selector)

Creates a sort, possibly in reverse, specifying how the sort value from the document's set is selected.

Declaration
public SortedSetSortField(string field, bool reverse, Selector selector)
Parameters
Type Name Description
string field

Name of field to sort by. Must not be null.
bool reverse

True if natural order should be reversed.
Selector selector

custom selector for choosing the sort value from the set.

NOTE: selectors other than MIN require optional codec support.

Properties

Selector

Returns the selector in use for this sort

Declaration
public Selector Selector { get; }
Property Value
Type Description
Selector

Methods

Equals(object)

Returns true if o is equal to this. If a Lucene.Net.Search.FieldComparerSource or Lucene.Net.Search.FieldCache.IParser was provided, it must properly implement equals (unless a singleton is always used).

Declaration
public override bool Equals(object obj)
Parameters
Type Name Description
object obj
Returns
Type Description
bool
Overrides

GetComparer(int, int)

Returns the Lucene.Net.Search.FieldComparer to use for sorting.

Note

This API is experimental and might change in incompatible ways in the next release.

Declaration
public override FieldComparer GetComparer(int numHits, int sortPos)
Parameters
Type Name Description
int numHits

Number of top hits the queue will store
int sortPos

Position of this Lucene.Net.Search.SortField within Lucene.Net.Search.Sort. The comparer is primary if sortPos==0, secondary if sortPos==1, etc. Some comparers can optimize themselves when they are the primary sort.
Returns
Type Description
FieldComparer

Lucene.Net.Search.FieldComparer to use when sorting
Overrides

GetHashCode()

Returns a hash code value for this object. If a Lucene.Net.Search.FieldComparerSource or Lucene.Net.Search.FieldCache.IParser was provided, it must properly implement GetHashCode() (unless a singleton is always used).

Declaration
public override int GetHashCode()
Returns
Type Description
int
Overrides
Lucene.Net.Search.SortField.GetHashCode()

SetMissingValue(object)

Set how missing values (the empty set) are sorted.

Note that this must be Lucene.Net.Search.SortField.STRING_FIRST or Lucene.Net.Search.SortField.STRING_LAST.
Declaration
public override void SetMissingValue(object value)
Parameters
Type Name Description
object value
Overrides

ToString()

Returns a string that represents the current object.

Declaration
public override string ToString()
Returns
Type Description
string

A string that represents the current object.
Overrides
Lucene.Net.Search.SortField.ToString()