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Interface RangeQuery

Builder for queries that select a range of events from a time series.

See Session.timeseries for an overview of the various types of range query:

  • value range queries,
  • latest edits edit range queries, and
  • all edits edit range queries.

rangeQuery returns a default RangeQuery. Further queries with different parameters can be configured using the methods of this interface. RangeQuery instances are immutable. Each method returns a copy of this query with a modified setting. Method calls can be chained together in a fluent manner to create a query. For example:

var defaultQuery = session.timeseries.rangeQuery();

// A value range query that selects up to 100 original events from the
// start of a time series.
first100 = defaultQuery.forValues().fromStart().next(100);

Creating value range queries

A value range query returns a merged view of part of a time series. This is the most common time series query and appropriate for most applications. A value range query begins with the forValues operator, followed by the view range. The view range determines the range of original events the time series that are of interest. See Range expressions below for the various ways to specify RANGE .

The events returned by the query are constrained by an optional edit range, introduced by the editRange operator. An event will only be included in the result if it is in the edit range. Let's consider some examples to see how the view range and the edit range interact.

Query Meaning
rangeQuery().forValues(); For each original event in the time series, either return the latest edit event or if it has no edit events, return the original event.
rangeQuery().forValues().from(100).to(150); For each original event with a sequence number between 100 and 150 (inclusive), either return the latest edit event or if it has no edit events, return the original event.
rangeQuery().forValues().from(100).to(150).editRange().from(400); For each original event with a sequence number between 100 and 150 (inclusive), return the latest edit event with a sequence number greater than or equal to 400.

The result of this query will not include any original events because there is no overlap between the view range and the edit range.

Value range queries can be further refined using the limit() and as() operators.

Creating edit range queries

An edit range query returns an unmerged view of a time series than can include both original events and the edit events that replace them. Edit range queries are rarely needed – value range queries satisfy most use cases.

An edit range query begins with the forEdits operator, followed by the view range. The view range determines the range of original events the time series that are of interest. The result will only contain original events that are in the view range, and edit events for original events in the view range. See Range expressions below for the various ways to specify RANGE .

The events returned by the query are constrained by an optional edit range, introduced by the latestEdits or allEdits operators. An event will only be included in the result if it is in the edit range. Let's consider some example edit range queries.

Query Meaning
rangeQuery().forEdits(); Return all events in a time series.
rangeQuery().forEdits().from(100).to(150); Return the original events with a sequence number between 100 and 150 (inclusive) and all edit events in the time series that refer to the original events.
rangeQuery().forEdits().from(100).to(150).latestEdits(); Return the original events with a sequence number between 100 and 150 (inclusive) and the latest edit events in the time series that refer to the original events.
rangeQuery().forEdits().from(100).to(150).allEdits().from(400); For each original event with a sequence number between 100 and 150, (inclusive) return all edit events with a sequence number greater than or equal to 400.

The result of this query will not include any original events because there is no overlap between the view range and the edit range.

Edit range queries can be further refined using the limit() and as() operators.

Range expressions

Range expressions are used to specify the view and edit ranges in value range and edit range queries. Each range expression has an anchor that determines where to start, and a span that determines where the range ends. Both anchor and span are inclusive – if an anchor or span falls on an event, the event is included in the result.

Both anchor and the span are optional. If the anchor is unspecified, the range begins at the start of the time series. If the span is unspecified, the range continues until the end of the time series.

Anchors

There are five ways to specify an anchor.

Anchor Meaning
from(Number) Sets the anchor at an absolute sequence number.
from(Date) Sets the anchor at an absolute time.
fromStart Sets the anchor at the start of the time series.
fromLast(Number) Sets the anchor at a relative offset before the end of the time series. For value range queries, count is the number of original events. For edit range queries, count is the number of events of any type.
fromLast(Date
fromLastMillis		 Sets the anchor at a relative time before the timestamp of the last event of the time series.

An anchor point can be before the start or after the end of the time series.

Spans

There are nine ways to specify a span.

Span Meaning
to(Number) The range ends at an absolute sequence number. The sequence argument may be before or after the anchor.
toStart The range ends at the start of the time series.
to(Date) The range ends at an absolute time. The date argument may be before or after the anchor.
next(Number) The range ends at an event that is a relative number of events after the anchor. For value range queries, count is the number of original events. For edit range queries, count is the number of events of any type.
next(Date)
nextMillis		 The range ends at an event that is a relative time after the anchor.
previous(Number) The range ends at an event that is a relative number of events before the anchor. For value range queries, count is the number of original events. For edit range queries, count is the number of events of any type.
previous(Date)
previousMillis		 The range ends at an event that is a relative time before the anchor.
untilLast(Number The range ends at an event that is a relative number of events before the end of the time series. For value range queries, count is the number of original events. For edit range queries, count is the number of events of any type.
untilLast(Date)
untilLastMillis		 The range ends at an event that is a relative time before the timestamp of the last event of the time series.

A span can specify an end point that is before the start or after the end of the time series.

If the span specifies an end point after the anchor, the range includes the first event at or following the anchor and ends at the last event at or preceding the end point. If the span specifies an end point before the anchor, the range includes the first event at or preceding the anchor and ends at the last event at or after the end point.

Using the builder methods

Although the natural order of operators in a query is as shown in the syntax diagrams above, RangeQuery builder methods – those that return another RangeQuery – can be applied in any order with the following exceptions:

Each method overrides some configuration of the RangeQuery to which it is applied, as summarized in the following table.

Builder method Operator type Overridden configuration
forValues() Value range Overrides the existing query type to create a new value range query. Overrides the existing view range with a new view range that selects the entire time series. The existing edit range is copied unchanged.
forEdits() Value range Overrides the existing query type to create a new edit range query that includes all edits. Overrides the existing view range with a new view range that selects the entire time series. The existing edit range is copied unchanged.
editRange() Edit range Overrides the existing edit range with a new edit range that selects the entire time series. The existing view range is copied unchanged.
Throws IllegalStateException if this is not a value range query.
latestEdits()
allEdits()		 Edit range Overrides the existing edit range with a new edit range that selects the entire time series. The existing view range is copied unchanged.
Throws Error if this is not an edit range query.
from()
fromStart()
fromLast()		 Anchor Overrides the anchor of the current range.
to()
toStart()
next()
previous()
untilLast()		 Span Overrides the span of the current range.
limit() Limit Overrides the limit.
as() Query value type Overrides the query value type.
see

Session.timeseries.rangeQuery

Hierarchy

  • RangeQuery

Index

Methods

Methods

allEdits

  • Return a copy of this RangeQuery configured to perform an edit range query with the edit range that selects all edits in the entire time series.

    This operator can only be applied to edit range queries. The default query returned by rangeQuery() is a value range query. The RangeQuery.forEdits operator can be used to create an edit range query form a value range query.

    Operator type: edit range

    throws

    an IllegalStateError if this is not an edit range query

    Returns RangeQuery

    a copy of this range query configured to perform an edit range query with a new edit range that selects all edits in the entire time series

as

  • Return a copy of this RangeQuery with a different query value type.

    A query can only be evaluated successfully against time series topics with a compatible event data type. If a query method is called for a time series topic with an incompatible event data type, the query will complete exceptionally.

    If the event data type of the time series topic is known, compatibility of a particular valueClass can be checked using canReadAs. The default range query has a query value type of Bytes, which is compatible with all time series value data types.

    Operator type: query value type

    throws

    an IllegalArgumentError if valueClass cannot be read as a data type

    throws

    a NullValueError if valueClass is null or undefined

    Parameters

    • valueClass: DataType<any, any, any> | object

      the value class or data type to read event values as

    Returns RangeQuery

    a copy of this range query with a new query value type

editRange

  • Return a copy of this RangeQuery configured to perform a value range query with the edit range set to the entire time series.

    This operator can only be applied to value range queries. The default query returned by rangeQuery() is a value range query. The RangeQuery.forValues operator can be used to create a value range query from an edit range query.

    Operator type: edit range

    throws

    an IllegalStateError if this is not a value range query

    Returns RangeQuery

    a copy of this range query configured to perform a view range query with a new edit range that selects the entire time series

forEdits

  • Return a copy of this RangeQuery configured to perform an edit range query within the view range set to the entire time series.

    Operator type: value range

    Returns RangeQuery

    a copy of this range query configured to perform an edit range query with a new view range that selects the entire time series

forValues

  • Return a copy of this RangeQuery configured to perform a value range query within the view range set to the entire time series.

    Operator type: value range

    Returns RangeQuery

    a copy of this range query configured to perform a view range query within a new view range that selects the time time series.

from

  • Return a copy of this RangeQuery with the anchor of the current range configured to be either an absolute sequence number, or a Date instance.

    Operator type: anchor

    throws

    an IllegalArgumentError if sequence is negative

    throws

    a NullValueError if sequence is null or undefined

    Parameters

    • sequence: number | Date

      absolute sequence number or Date specifying the anchor of the returned range

    Returns RangeQuery

    a copy of this range query with a new anchor

fromLast

  • Return a copy of this RangeQuery with the anchor of the current range configured to be a relative offset before the end of the time series.

    Operator type: anchor

    throws

    an IllegalArgumentError if count is negative

    throws

    a NullValueError if count is null or undefined

    Parameters

    • count: number

      specifies the anchor as a number of events before the end of the time series. For value range queries, count is the number of original events. For edit range queries, count is the number of events of any type.

    Returns RangeQuery

    a copy of this range query with a new anchor

fromLastMillis

  • Return a copy of this RangeQuery with the anchor of the current range configured to be a relative time from the timestamp of the last event in the time series.

    Operator type: anchor

    throws

    an IllegalArgumentError if timeSpan is negative

    throws

    a NullValueError if timeSpan is null or undefined

    Parameters

    • timeSpan: number

      specifies anchor as a number of milliseconds relative to the timestamp of the latest event in the time series

    Returns RangeQuery

    a copy of this range query with a new anchor

fromStart

  • Return a copy of this RangeQuery with the anchor of the current range configured to be the start of the time series.

    There is a difference between fromStart( and from(0) if the range also ends before the first event of the time series. For example, fromStart().toStart() is always empty, but from(0).toStart() includes the event with sequence number 0 .

    Operator type: anchor

    Returns RangeQuery

    a copy of this range query with a new anchor

latestEdits

  • Return a copy of this RangeQuery configured to perform an edit range query with the edit range that selects latest edits in the entire time series.

    This operator can only be applied to edit range queries. The default query returned by rangeQuery() is a value range query. The forEdits() operator can be used to create an edit range query from a value range query.

    Operator type: edit range

    throws

    an IllegalStateError if this is not an edit range query

    Returns RangeQuery

    a copy of this range query configured to perform an edit range query with a new edit range that selects the latest edits in the entire time series

limit

  • Return a copy of this RangeQuery that returns at most count events.

    If the query would otherwise select more than count events, only the latest count values (those with the highest sequence numbers) are returned.

    This is most useful when a temporal span has been configured with RangeQuery.nextMillis or RangeQuery.previousMillis, where the potential number of returned events is unknown.

    isComplete() can be used to determine whether a query has returned an incomplete result.

    Operator type: limit

    throws

    an IllegalArgumentError if count is negative

    Parameters

    • count: number

      the maximum number of events to return

    Returns RangeQuery

    a copy of this range query with a new limit

next

  • Return a copy of this RangeQuery with the span of the current range configured to select a range of events following the anchor.

    Operator type: span

    throws

    an IllegalArgumentError if count is negative

    throws

    a NullValueError if count is null or undefined

    Parameters

    • count: number

      specifies the end of the range of events to select following the anchor. For value range queries, count is the number of original events. For edit range queries, count is the number of events of any type.

    Returns RangeQuery

    a copy of this range query with a new span

nextMillis

  • Return a copy of this RangeQuery with the span of the current range configured to select a temporal range of events following the anchor.

    Operator type: span

    throws

    an IllegalArgumentError if timeSpan is negative

    throws

    a NullValueError if timeSpan is null or undefined

    Parameters

    • timeSpan: number

      the time span in milliseconds of events following the anchor to select

    Returns RangeQuery

    a copy of this range query with a new span

previous

  • Return a copy of this RangeQuery with the span of the current range configured to select a range of events preceding the anchor.

    Operator type: span

    throws

    an IllegalArgumentError if count is negative

    Parameters

    • count: number

      specifies the end of the range of events to select preceding the anchor. For value range queries, count is the number of original events. For edit range queries, count is the number of events of any type.

    Returns RangeQuery

    a copy of this range query with a new span

previousMillis

  • Return a copy of this RangeQuery with the span of the current range configured to select a temporal range of events preceding the anchor.

    Operator type: span

    throws

    an IllegalArgumentError if timeSpan is negative

    Parameters

    • timeSpan: number

      the time span in milliseconds of events preceding the anchor to select

    Returns RangeQuery

    a copy of this range query with a new span

selectFrom

  • Evaluate this query for a time series topic.

    The session must have the READ_TOPIC path permission for topicPath to evaluate a query. The QUERY_OBSOLETE_TIME_SERIES_EVENTS topic permission is also required if this is an edit range query, or a value range query with an edit range.

    Parameters

    • topicPath: string

      the path of the time series topic to query

    Returns Result<QueryResult>

    a result that completes when a response is received from the server.

    If the query returned results, the result will complete successfully and provide an QueryResult.

    Otherwise, the result will complete exceptionally with an ErrorReason.

to

  • Return a copy of this RangeQuery with the span of the current range configured to end at an absolute sequence number or Date instance.

    Operator type: span

    throws

    an IllegalArgumentError if sequence is negative

    throws

    a NullValueError if sequence is null or undefined

    Parameters

    • sequence: number | Date

      absolute sequence number or Date instance specifying the end of the returned range

    Returns RangeQuery

    a copy of this range query with a new span

toStart

  • Return a copy of this RangeQuery with the span of the current range configured to end at the start of the time series.

    There is a difference between toStart() and to(0) if the range also starts before the first event of the time series. For example, fromStart().toStart() is always empty, but fromStart().to(0) includes the event with sequence number 0 .

    Operator type: span

    Returns RangeQuery

    a copy of this range query with a new span

untilLast

  • Return a copy of this RangeQuery with the span of the current range configured to end a number of events before the end of the time series.

    Operator type: span

    throws

    an IllegalArgumentError if count is negative

    throws

    a NullValueError if count is null or undefined

    Parameters

    • count: number

      specifies the end of the range of events to select as a number of events before the end of the time series. For value range queries, count is the number of original events. For edit range queries, count is the number of events of any type.

    Returns RangeQuery

    a copy of this range query with a new span

untilLastMillis

  • Return a copy of this RangeQuery with the span of the current range configured to end at a relative time from the timestamp of the last event in the time series.

    Operator type: span

    throws

    an IllegalArgumentError if timeSpan is negative

    throws

    a NullValueError if timeSpan is null or undefined

    Parameters

    • timeSpan: number

      specifies the end of the range of events to select as a number of milliseconds relative to the timestamp of the latest event in the time series

    Returns RangeQuery

    a copy of this range query with a new span