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Query types

Every query derives from Query. Built-in queries live in Rowles.LeanCorpus.Search.Queries.

Choose the narrowest query that expresses the requirement. Exact term and point queries can seek directly to compact index structures. Patterns, broad alternatives, and positional trees do more expansion or verification work.

Exact terms and sets

Query Use it for Notes
TermQuery One exact indexed term Input is not analysed automatically. Best basic primitive for exact or pre-analysed terms.
TermInSetQuery Any term from a set Prefer it to a very large Boolean OR of term queries.
TermsQuery Any exact UTF-8 term from a set Avoids string conversion during term-dictionary lookup.
FieldExistsQuery Documents with a value Uses indexed field data rather than stored-field retrieval.
MatchAllDocsQuery Every live document Often combined with filters, sorting, or aggregations.
MatchNoDocsQuery No documents Useful as an explicit empty rewrite result. 
var one = new TermQuery("status", "published");
var any = new TermInSetQuery("category", ["books", "music", "games"]);

Compound and scoring queries

Query Use it for Notes
BooleanQuery Required, optional, and excluded clauses Use Must, Should, and MustNot; see Boolean queries.
DisjunctionMaxQuery Best matching field or clause Adds a configurable fraction of scores from other matching clauses.
CombinedFieldsQuery One analysed term set across several text fields Useful when fields represent one logical body with different weights.
ConstantScoreQuery Matching without similarity-based score variation Wraps another query and assigns a fixed score.
FunctionScoreQuery Combine a query score with a numeric field Useful for recency, popularity, or business signals.
FunctionQuery Rank every live document from a value source Uses a DoubleValuesSource directly.
RrfQuery Fuse independently ranked child queries Reciprocal rank fusion avoids comparing unlike score scales directly.

Phrase, span, and intervals

These queries require indexed positions.

Query Use it for Notes
PhraseQuery Ordered terms with optional gaps The simplest phrase form.
MultiPhraseQuery Alternatives at one or more phrase positions Supports explicit positions and slop.
SpanTermQuery A term represented as a span Leaf for other span queries.
SpanNearQuery Ordered or unordered span proximity Composes span leaves or other span queries.
SpanOrQuery Alternative spans All clauses must target the same field.
SpanNotQuery Include spans from documents without an excluded span Exclusion currently applies to the whole document.
SpanFirstQuery Spans ending before a field position Wraps any span query.
SpanContainingQuery Enclosing spans containing another span Both clauses target the same field.
SpanWithinQuery Inner spans contained by another span Both clauses target the same field.
FieldMaskingSpanQuery Treat one field's positions as another field Enables cross-field positional composition.
SpanMultiTermQueryWrapper Position-aware multi-term expansion Supports prefix, wildcard, fuzzy, regex, and term ranges.
IntervalsQuery Ordered, unordered, alternative, containment, or exclusion trees Best for a complex positional expression.

See Phrase and proximity and Intervals.

Multi-term text queries

Query Use it for Cost controls
PrefixQuery Terms beginning with a fixed prefix Longer fixed prefixes reduce dictionary expansion.
WildcardQuery * and ? patterns Avoid leading wildcards on large term dictionaries.
RegexpQuery Regular-expression term matching Bound user patterns and test worst cases.
FuzzyQuery Terms within edit distance 0 to 2 MaxExpansions limits candidate terms.
TermRangeQuery Lexicographic term range Bounds may be inclusive, exclusive, or null for unbounded. 
var names = new TermRangeQuery(
    "surname",
    lowerTerm: "m",
    upperTerm: "r",
    includeLower: true,
    includeUpper: false);

TermRangeQuery compares indexed terms lexicographically. It is not a numeric range query and "100" does not sort numerically before "20".

Numeric and point queries

Query Use it for Notes
RangeQuery Inclusive double range over NumericField BKD-backed.
Int64RangeQuery Inclusive 64-bit integer range Preserves integer precision.
PointInSetQuery Any double value from a set Useful for non-contiguous numeric filters.
Int64PointInSetQuery Any 64-bit integer from a set Avoids conversion through double. 
var price = new RangeQuery("price", min: 10.0, max: 25.0);
var ids = new Int64PointInSetQuery("accountId", [12L, 48L, 91L]);

Specialised queries

Query Use it for Guide
VectorQuery Exact or HNSW nearest-neighbour search, optionally filtered Vector search
BlockJoinQuery Parent documents whose child documents match Block join
MoreLikeThisQuery Documents similar to source text or a source document More Like This
GeoBoundingBoxQuery Points inside a latitude/longitude rectangle Geo search
GeoDistanceQuery Points within a radius Geo search

Run a query

var query = new TermQuery("title", "fox");
var hits = searcher.Search(query, topN: 10);

Search returns TopDocs, containing total-hit information and ordered ScoreDoc values. Query boosts affect scoring and form part of query-cache identity.

For user query strings, use the query parser or analyse input deliberately. Constructors generally expect indexed terms, not raw natural-language text.

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