Firestore v1 API - Class StructuredQuery (3.5.0) 

public sealed class StructuredQuery : IMessage<StructuredQuery>, IEquatable<StructuredQuery>, IDeepCloneable<StructuredQuery>, IBufferMessage, IMessage

Reference documentation and code samples for the Firestore v1 API class StructuredQuery.

A Firestore query.

The query stages are executed in the following order:

  1. from
  2. where
  3. select
  4. order_by + start_at + end_at
  5. offset
  6. limit

Inheritance

object > StructuredQuery

Namespace

Google.Cloud.Firestore.V1

Assembly

Google.Cloud.Firestore.V1.dll

Constructors

StructuredQuery()

public StructuredQuery()

StructuredQuery(StructuredQuery)

public StructuredQuery(StructuredQuery other)
Parameter
NameDescription
otherStructuredQuery

Properties

EndAt

public Cursor EndAt { get; set; }

A potential prefix of a position in the result set to end the query at.

This is similar to START_AT but with it controlling the end position rather than the start position.

Requires:

  • The number of values cannot be greater than the number of fields specified in the ORDER BY clause.
Property Value
TypeDescription
Cursor

From

public RepeatedField<StructuredQuery.Types.CollectionSelector> From { get; }

The collections to query.

Property Value
TypeDescription
RepeatedFieldStructuredQueryTypesCollectionSelector

Limit

public int? Limit { get; set; }

The maximum number of results to return.

Applies after all other constraints.

Requires:

  • The value must be greater than or equal to zero if specified.
Property Value
TypeDescription
int

Offset

public int Offset { get; set; }

The number of documents to skip before returning the first result.

This applies after the constraints specified by the WHERE, START AT, & END AT but before the LIMIT clause.

Requires:

  • The value must be greater than or equal to zero if specified.
Property Value
TypeDescription
int

OrderBy

public RepeatedField<StructuredQuery.Types.Order> OrderBy { get; }

The order to apply to the query results.

Firestore allows callers to provide a full ordering, a partial ordering, or no ordering at all. In all cases, Firestore guarantees a stable ordering through the following rules:

  • The order_by is required to reference all fields used with an inequality filter.
  • All fields that are required to be in the order_by but are not already present are appended in lexicographical ordering of the field name.
  • If an order on __name__ is not specified, it is appended by default.

Fields are appended with the same sort direction as the last order specified, or 'ASCENDING' if no order was specified. For example:

  • ORDER BY a becomes ORDER BY a ASC, __name__ ASC
  • ORDER BY a DESC becomes ORDER BY a DESC, __name__ DESC
  • WHERE a > 1 becomes WHERE a > 1 ORDER BY a ASC, __name__ ASC
  • WHERE __name__ > ... AND a > 1 becomes WHERE __name__ > ... AND a > 1 ORDER BY a ASC, __name__ ASC
Property Value
TypeDescription
RepeatedFieldStructuredQueryTypesOrder

Select

public StructuredQuery.Types.Projection Select { get; set; }

Optional sub-set of the fields to return.

This acts as a [DocumentMask][google.firestore.v1.DocumentMask] over the documents returned from a query. When not set, assumes that the caller wants all fields returned.

Property Value
TypeDescription
StructuredQueryTypesProjection

StartAt

public Cursor StartAt { get; set; }

A potential prefix of a position in the result set to start the query at.

The ordering of the result set is based on the ORDER BY clause of the original query.

SELECT * FROM k WHERE a = 1 AND b > 2 ORDER BY b ASC, __name__ ASC;

This query's results are ordered by (b ASC, __name__ ASC).

Cursors can reference either the full ordering or a prefix of the location, though it cannot reference more fields than what are in the provided ORDER BY.

Continuing off the example above, attaching the following start cursors will have varying impact:

  • START BEFORE (2, /k/123): start the query right before a = 1 AND b > 2 AND __name__ > /k/123.
  • START AFTER (10): start the query right after a = 1 AND b > 10.

Unlike OFFSET which requires scanning over the first N results to skip, a start cursor allows the query to begin at a logical position. This position is not required to match an actual result, it will scan forward from this position to find the next document.

Requires:

  • The number of values cannot be greater than the number of fields specified in the ORDER BY clause.
Property Value
TypeDescription
Cursor

Where

public StructuredQuery.Types.Filter Where { get; set; }

The filter to apply.

Property Value
TypeDescription
StructuredQueryTypesFilter