jOOL 0.9.15 · org.jooq.lambda.Window · APIdia, the JavaDoc alternative

A window containing the data for its partition, to perform calculations upon.

Window functions as exposed in this type are inspired by their counterparts in SQL. They include:

Ranking functions

Ranking functions are useful to determine the "rank" of any given row within the partition, given a specific ordering. The following table explains individual ranking functions:

Function	Description
`rowNumber()`	The distinct row number of the row within the partition, counting from `0`.
`rank()`	The rank with gaps of a row within the partition, counting from `0`.
`denseRank()`	The rank without gaps of a row within the partition, counting from `0`.
`percentRank()`	Relative rank of a row: `rank()` / `count()`.
`ntile(long)`	Divides the partition in equal buckets and assigns values between `0` and `buckets - 1`.
`lead()`	Gets the value after the current row.
`lag()`	Gets the value before the current row.
`firstValue()`	Gets the first value in the window.
`lastValue()`	Gets the last value in the window.
`nthValue(long)`	Gets the nth value in the window, counting from `0`.

Note: In Java, indexes are always counted from 0, not from 1 as in SQL. This means that the above ranking functions also rank rows from zero. This is particularly true for:

Aggregate functions

Each aggregate function from Seq or from Agg is also available as an aggregate function on the window. For instance, count() is the same as calling Seq#count() on window()

Method Summary

Modifier and Type	Method and Description
public long	denseRank() The dense rank of the current row within the partition.
public Optional<T>	firstValue() The first value in the window.
public <U> Optional<U>	firstValue(Function<? super T, ? extends U> function) The first value in the window.
public Optional<T>	lag() The previous value in the window.
public Optional<T>	lag(long lag) The previous value by `lag` in the window.
public Optional<T>	lastValue() The last value in the window.
public <U> Optional<U>	lastValue(Function<? super T, ? extends U> function) The last value in the window.
public Optional<T>	lead() The next value in the window.
public Optional<T>	lead(long lead) The next value by `lead` in the window.
public Optional<T>	nthValue(long n) The nth value in the window.
public <U> Optional<U>	nthValue(long n, Function<? super T, ? extends U> function) The nth value in the window.
public long	ntile(long buckets) The bucket number ("ntile") of the current row within the partition.
public static <T> WindowSpecification<T>	of()
public static <T> WindowSpecification<T>	of(long lower, long upper)
public static <T> WindowSpecification<T>	of(Comparator<? super T> orderBy)
public static <T> WindowSpecification<T>	of(Comparator<? super T> orderBy, long lower, long upper)
public static <T, U> WindowSpecification<T>	of(Function<? super T, ? extends U> partitionBy)
public static <T, U> WindowSpecification<T>	of(Function<? super T, ? extends U> partitionBy, long lower, long upper)
public static <T, U> WindowSpecification<T>	of(Function<? super T, ? extends U> partitionBy, Comparator<? super T> orderBy)
public static <T, U> WindowSpecification<T>	of(Function<? super T, ? extends U> partitionBy, Comparator<? super T> orderBy, long lower, long upper)
public double	percentRank() The precent rank of the current row within the partition.
public long	rank() The rank of the current row within the partition.
public long	rowNumber() The row number of the current row within the partition.
public T	value() The value of the current row in the window.
public Seq<T>	window() Stream all elements in the window.

Method Detail

denseRank back to summary

denseRank	back to summary
public long denseRank() The dense rank of the current row within the partition. `// (1, 2, 2, 3, 4) Seq.of(1, 2, 2, 3, 4).window(naturalOrder()).map(w -> w.denseRank());`

public long denseRank()

The dense rank of the current row within the partition.


// (1, 2, 2, 3, 4)
Seq.of(1, 2, 2, 3, 4).window(naturalOrder()).map(w -> w.denseRank());

firstValue back to summary

firstValue	back to summary
public Optional<T> firstValue() The first value in the window. `// (1, 1, 1, 1, 1) Seq.of(1, 2, 4, 2, 3).window().map(w -> w.firstValue());`

public Optional<T> firstValue()

The first value in the window.


// (1, 1, 1, 1, 1)
Seq.of(1, 2, 4, 2, 3).window().map(w -> w.firstValue());

firstValue back to summary

firstValue	back to summary
public <U> Optional<U> firstValue(Function<? super T, ? extends U> function) The first value in the window. `// (1, 1, 1, 1, 1) Seq.of(1, 2, 4, 2, 3).window().map(w -> w.firstValue());`

public Optional firstValue(Function<? super T, ? extends U> function)

The first value in the window.


// (1, 1, 1, 1, 1)
Seq.of(1, 2, 4, 2, 3).window().map(w -> w.firstValue());

lag back to summary

lag	back to summary
public Optional<T> lag() The previous value in the window. This is the same as calling `lag(1)` `// (empty, 1, 2, 2, 3) Seq.of(1, 2, 2, 3, 4).window().map(w -> w.lag());`

public Optional<T> lag()

The previous value in the window.

This is the same as calling lag(1)


// (empty, 1, 2, 2, 3)
Seq.of(1, 2, 2, 3, 4).window().map(w -> w.lag());

lag back to summary

lag	back to summary
public Optional<T> lag(long lag) The previous value by `lag` in the window. `// (empty, 1, 2, 2, 3) Seq.of(1, 2, 2, 3, 4).window().map(w -> w.lag());`

public Optional<T> lag(long lag)

The previous value by lag in the window.


// (empty, 1, 2, 2, 3)
Seq.of(1, 2, 2, 3, 4).window().map(w -> w.lag());

lastValue back to summary

lastValue	back to summary
public Optional<T> lastValue() The last value in the window. `// (3, 3, 3, 3, 3) Seq.of(1, 2, 4, 2, 3).window().map(w -> w.lastValue());`

public Optional<T> lastValue()

The last value in the window.


// (3, 3, 3, 3, 3)
Seq.of(1, 2, 4, 2, 3).window().map(w -> w.lastValue());

lastValue back to summary

lastValue	back to summary
public <U> Optional<U> lastValue(Function<? super T, ? extends U> function) The last value in the window. `// (3, 3, 3, 3, 3) Seq.of(1, 2, 4, 2, 3).window().map(w -> w.lastValue());`

public Optional lastValue(Function<? super T, ? extends U> function)

The last value in the window.


// (3, 3, 3, 3, 3)
Seq.of(1, 2, 4, 2, 3).window().map(w -> w.lastValue());

lead back to summary

lead	back to summary
public Optional<T> lead() The next value in the window. This is the same as calling `lead(1)` `// (2, 2, 3, 4, empty) Seq.of(1, 2, 2, 3, 4).window().map(w -> w.lead());`

public Optional<T> lead()

The next value in the window.

This is the same as calling lead(1)


// (2, 2, 3, 4, empty)
Seq.of(1, 2, 2, 3, 4).window().map(w -> w.lead());

lead back to summary

lead	back to summary
public Optional<T> lead(long lead) The next value by `lead` in the window. `// (2, 2, 3, 4, empty) Seq.of(1, 2, 2, 3, 4).window().map(w -> w.lead());`

public Optional<T> lead(long lead)

The next value by lead in the window.


// (2, 2, 3, 4, empty)
Seq.of(1, 2, 2, 3, 4).window().map(w -> w.lead());

nthValue back to summary

nthValue	back to summary
public Optional<T> nthValue(long n) The nth value in the window. `// (4, 4, 4, 4, 4) Seq.of(1, 2, 4, 2, 3).window().map(w -> w.nthValue(2));`

public Optional<T> nthValue(long n)

The nth value in the window.


// (4, 4, 4, 4, 4)
Seq.of(1, 2, 4, 2, 3).window().map(w -> w.nthValue(2));

nthValue back to summary

nthValue	back to summary
public <U> Optional<U> nthValue(long n, Function<? super T, ? extends U> function) The nth value in the window. `// (4, 4, 4, 4, 4) Seq.of(1, 2, 4, 2, 3).window().map(w -> w.nthValue(2));`

public Optional nthValue(long n, Function<? super T, ? extends U> function)

The nth value in the window.


// (4, 4, 4, 4, 4)
Seq.of(1, 2, 4, 2, 3).window().map(w -> w.nthValue(2));

ntile back to summary

ntile	back to summary
public long ntile(long buckets) The bucket number ("ntile") of the current row within the partition. `// (0, 0, 1, 1, 2) Seq.of(1, 2, 2, 3, 4).window(naturalOrder()).map(w -> w.ntile(3));`

public long ntile(long buckets)

The bucket number ("ntile") of the current row within the partition.


// (0, 0, 1, 1, 2)
Seq.of(1, 2, 2, 3, 4).window(naturalOrder()).map(w -> w.ntile(3));

of	back to summary
public static <T> WindowSpecification<T> of()

of	back to summary
public static <T> WindowSpecification<T> of(long lower, long upper)

of	back to summary
public static <T> WindowSpecification<T> of(Comparator<? super T> orderBy)

of	back to summary
public static <T> WindowSpecification<T> of(Comparator<? super T> orderBy, long lower, long upper)

of	back to summary
public static <T, U> WindowSpecification<T> of(Function<? super T, ? extends U> partitionBy)

of	back to summary
public static <T, U> WindowSpecification<T> of(Function<? super T, ? extends U> partitionBy, long lower, long upper)

of	back to summary
public static <T, U> WindowSpecification<T> of(Function<? super T, ? extends U> partitionBy, Comparator<? super T> orderBy)

of	back to summary
public static <T, U> WindowSpecification<T> of(Function<? super T, ? extends U> partitionBy, Comparator<? super T> orderBy, long lower, long upper)

percentRank back to summary

percentRank	back to summary
public double percentRank() The precent rank of the current row within the partition. `// (0.0, 0.25, 0.25, 0.75, 1.0) Seq.of(1, 2, 2, 3, 4).window(naturalOrder()).map(w -> w.percentRank());`

public double percentRank()

The precent rank of the current row within the partition.


// (0.0, 0.25, 0.25, 0.75, 1.0)
Seq.of(1, 2, 2, 3, 4).window(naturalOrder()).map(w -> w.percentRank());

rank back to summary

rank	back to summary
public long rank() The rank of the current row within the partition. `// (1, 2, 2, 4, 5) Seq.of(1, 2, 2, 3, 4).window(naturalOrder()).map(w -> w.rank());`

public long rank()

The rank of the current row within the partition.


// (1, 2, 2, 4, 5)
Seq.of(1, 2, 2, 3, 4).window(naturalOrder()).map(w -> w.rank());

rowNumber back to summary

rowNumber	back to summary
public long rowNumber() The row number of the current row within the partition. `// (1, 2, 3, 4, 5) Seq.of(1, 2, 4, 2, 3).window().map(w -> w.rowNumber());`

public long rowNumber()

The row number of the current row within the partition.


// (1, 2, 3, 4, 5)
Seq.of(1, 2, 4, 2, 3).window().map(w -> w.rowNumber());

value	back to summary
public T value() The value of the current row in the window.

window	back to summary
public Seq<T> window() Stream all elements in the window.

public Interface Window<T>

Ranking functions

Aggregate functions

Method Summary

Method Detail