Array Functions Reference

Array Functions Reference

Preview — Firestore in Native mode (with Pipeline Operations) for Enterprise Edition

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Array Functions

Name	Description
ARRAY	Returns an ARRAY containing one element for each input argument
ARRAY_CONCAT	Concatenates multiple arrays into a single ARRAY
ARRAY_CONTAINS	Returns TRUE if a given ARRAY contains a particular value
ARRAY_CONTAINS_ALL	Returns TRUE if all values are present in the ARRAY
ARRAY_CONTAINS_ANY	Returns TRUE if any of the values are present in the ARRAY
ARRAY_GET	Returns the element at a given index in an ARRAY
ARRAY_LENGTH	Returns the number of elements in an ARRAY
ARRAY_REVERSE	Reverses the order of elements in an ARRAY
SUM	Returns the sum of all NUMERIC values in an ARRAY.
JOIN	Produces a concatenation of the elements in an ARRAY as a STRING value.

ARRAY

Syntax:

array(values: ANY...) -> ARRAY

Description:

Constructs an array from the given elements.

• If an argument does not exist, it is replaced with NULL in the resulting array.

Examples:

values	array(values)
()	[]
(1, 2, 3)	[1, 2, 3]
("a", 1, true)	["a", 1, true]
(1, null)	[1, null]
(1, [2, 3])	[1, [2, 3]]

ARRAY_CONCAT

Syntax:

array_concat(arrays: ARRAY...) -> ARRAY

Description:

Concatenates two or more arrays into a single ARRAY.

Examples:

arrays	array_concat(arrays)
([1, 2], [3, 4])	[1, 2, 3, 4]
(["a", "b"], ["c"])	["a", "b", "c"]
([1], [2], [3])	[1, 2, 3]
([], [1, 2])	[1, 2]

Node.js

const result = await db.pipeline()
  .collection("books")
  .select(field("genre").arrayConcat([field("subGenre")]).as("allGenres"))
  .execute();
test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("genre").arrayConcat([Field("subGenre")]).as("allGenres")])
  .execute()
PipelineSnippets.swift

Kotlin
Android

val result = db.pipeline()
    .collection("books")
    .select(field("genre").arrayConcat(field("subGenre")).alias("allGenres"))
    .execute()
DocSnippets.kt

Java
Android

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("genre").arrayConcat(field("subGenre")).alias("allGenres"))
    .execute();
DocSnippets.java
    

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("genre").array_concat(Field.of("subGenre")).as_("allGenres"))
    .execute()
)
firestore_pipelines.py

Java

Pipeline.Snapshot result =
    firestore
        .pipeline()
        .collection("books")
        .select(arrayConcat(field("genre"), field("subGenre")).as("allGenres"))
        .execute()
        .get();
PipelineSnippets.java

ARRAY_CONTAINS

Syntax:

array_contains(array: ARRAY, value: ANY) -> BOOLEAN

Description:

Returns TRUE if value is found in the array, and FALSE otherwise.

Examples:

array	value	array_contains(array, value)
[1, 2, 3]	2	true
[[1, 2], [3]]	[1, 2]	true
[1, null]	null	true
"abc"	ANY	error

Node.js

const result = await db.pipeline()
  .collection("books")
  .select(field("genre").arrayContains(constant("mystery")).as("isMystery"))
  .execute();
test.firestore.js

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("genre").arrayContains(constant("mystery")).as("isMystery"))
);
test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("genre").arrayContains(Constant("mystery")).as("isMystery")])
  .execute()
PipelineSnippets.swift

Kotlin
Android

val result = db.pipeline()
    .collection("books")
    .select(field("genre").arrayContains("mystery").alias("isMystery"))
    .execute()
DocSnippets.kt

Java
Android

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("genre").arrayContains("mystery").alias("isMystery"))
    .execute();
DocSnippets.java
    

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("genre").array_contains("mystery").as_("isMystery"))
    .execute()
)
firestore_pipelines.py

Java

Pipeline.Snapshot result =
    firestore
        .pipeline()
        .collection("books")
        .select(arrayContains(field("genre"), "mystery").as("isMystery"))
        .execute()
        .get();
PipelineSnippets.java

ARRAY_CONTAINS_ALL

Syntax:

array_contains_all(array: ARRAY, search_values: ARRAY) -> BOOLEAN

Description:

Returns TRUE if all search_values are found in the array, and FALSE otherwise.

Examples:

array	search_values	array_contains_all(array, search_values)
[1, 2, 3]	[1, 2]	true
[1, 2, 3]	[1, 4]	false
[1, null]	[null]	true
[NaN]	[NaN]	true
[]	[]	true
[1, 2, 3]	[]	true

Node.js

const result = await db.pipeline()
  .collection("books")
  .select(
    field("genre")
      .arrayContainsAll([constant("fantasy"), constant("adventure")])
      .as("isFantasyAdventure")
  )
  .execute();
test.firestore.js

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(
    field("genre")
      .arrayContainsAll([constant("fantasy"), constant("adventure")])
      .as("isFantasyAdventure")
  )
);
test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([
    Field("genre")
      .arrayContainsAll([Constant("fantasy"), Constant("adventure")])
      .as("isFantasyAdventure")
  ])
  .execute()
PipelineSnippets.swift

Kotlin
Android

val result = db.pipeline()
    .collection("books")
    .select(
        field("genre")
            .arrayContainsAll(listOf("fantasy", "adventure"))
            .alias("isFantasyAdventure")
    )
    .execute()
DocSnippets.kt

Java
Android

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(
        field("genre")
            .arrayContainsAll(Arrays.asList("fantasy", "adventure"))
            .alias("isFantasyAdventure")
    )
    .execute();
DocSnippets.java
    

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(
        Field.of("genre")
        .array_contains_all(["fantasy", "adventure"])
        .as_("isFantasyAdventure")
    )
    .execute()
)
firestore_pipelines.py

Java

Pipeline.Snapshot result =
    firestore
        .pipeline()
        .collection("books")
        .select(
            arrayContainsAll(field("genre"), Arrays.asList("fantasy", "adventure"))
                .as("isFantasyAdventure"))
        .execute()
        .get();
PipelineSnippets.java

ARRAY_CONTAINS_ANY

Syntax:

array_contains_any(array: ARRAY, search_values: ARRAY) -> BOOLEAN

Description:

Returns TRUE if any of the search_values are found in the array, and FALSE otherwise.

Examples:

array	search_values	array_contains_any(array, search_values)
[1, 2, 3]	[4, 1]	true
[1, 2, 3]	[4, 5]	false
[1, 2, null]	[null]	true

Node.js

const result = await db.pipeline()
  .collection("books")
  .select(
    field("genre")
      .arrayContainsAny([constant("fantasy"), constant("nonfiction")])
      .as("isMysteryOrFantasy")
  )
  .execute();
test.firestore.js

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(
    field("genre")
      .arrayContainsAny([constant("fantasy"), constant("nonfiction")])
      .as("isMysteryOrFantasy")
  )
);
test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([
    Field("genre")
      .arrayContainsAny([Constant("fantasy"), Constant("nonfiction")])
      .as("isMysteryOrFantasy")
  ])
  .execute()
PipelineSnippets.swift

Kotlin
Android

val result = db.pipeline()
    .collection("books")
    .select(
        field("genre")
            .arrayContainsAny(listOf("fantasy", "nonfiction"))
            .alias("isMysteryOrFantasy")
    )
    .execute()
DocSnippets.kt

Java
Android

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(
        field("genre")
            .arrayContainsAny(Arrays.asList("fantasy", "nonfiction"))
            .alias("isMysteryOrFantasy")
    )
    .execute();
DocSnippets.java
    

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(
        Field.of("genre")
        .array_contains_any(["fantasy", "nonfiction"])
        .as_("isMysteryOrFantasy")
    )
    .execute()
)
firestore_pipelines.py

Java

Pipeline.Snapshot result =
    firestore
        .pipeline()
        .collection("books")
        .select(
            arrayContainsAny(field("genre"), Arrays.asList("fantasy", "nonfiction"))
                .as("isMysteryOrFantasy"))
        .execute()
        .get();
PipelineSnippets.java

ARRAY_GET

Syntax:

array_get(array: ARRAY, index: INT64) -> ANY

Description:

Returns the element at the 0-based index in array.

• If index is negative, elements are accessed from the end of array, where -1 is the last element.
• If array is not of type ARRAY, the function returns an absent value.
• If index is out of bounds, the function returns an absent value.
• If index is not of type INT64, the function returns an error.

Examples:

array	index	array_get(array, index)
[1, 2, 3]	0	1
[1, 2, 3]	-1	3
[1, 2, 3]	3	absent
[1, 2, 3]	-4	absent
"abc"	0	absent
null	0	absent
Array	"a"	error
Array	2.0	error

ARRAY_LENGTH

Syntax:

array_length(array: ARRAY) -> INT64

Description:

Returns the number of elements in array.

Examples:

array	array_length(array)
[1, 2, 3]	3
[]	0
[1, 1, 1]	3
[1, null]	2

Node.js

const result = await db.pipeline()
  .collection("books")
  .select(field("genre").arrayLength().as("genreCount"))
  .execute();
test.firestore.js

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("genre").arrayLength().as("genreCount"))
);
test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("genre").arrayLength().as("genreCount")])
  .execute()
PipelineSnippets.swift

Kotlin
Android

val result = db.pipeline()
    .collection("books")
    .select(field("genre").arrayLength().alias("genreCount"))
    .execute()
DocSnippets.kt

Java
Android

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("genre").arrayLength().alias("genreCount"))
    .execute();
DocSnippets.java
    

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("genre").array_length().as_("genreCount"))
    .execute()
)
firestore_pipelines.py

Java

Pipeline.Snapshot result =
    firestore
        .pipeline()
        .collection("books")
        .select(arrayLength(field("genre")).as("genreCount"))
        .execute()
        .get();
PipelineSnippets.java

ARRAY_REVERSE

Syntax:

array_reverse(array: ARRAY) -> ARRAY

Description:

Reverses the given array.

Examples:

array	array_reverse(array)
[1, 2, 3]	[3, 2, 1]
["a", "b"]	["b", "a"]
[1, 2, 2, 3]	[3, 2, 2, 1]

Node.js

const result = await db.pipeline()
  .collection("books")
  .select(arrayReverse(field("genre")).as("reversedGenres"))
  .execute();
test.firestore.js

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("genre").arrayReverse().as("reversedGenres"))
);
test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("genre").arrayReverse().as("reversedGenres")])
  .execute()
PipelineSnippets.swift

Kotlin
Android

val result = db.pipeline()
    .collection("books")
    .select(field("genre").arrayReverse().alias("reversedGenres"))
    .execute()
DocSnippets.kt

    
Java
Android
Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("genre").arrayReverse().alias("reversedGenres"))
    .execute();
DocSnippets.java
  

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("genre").array_reverse().as_("reversedGenres"))
    .execute()
)
firestore_pipelines.py

Java

Pipeline.Snapshot result =
    firestore
        .pipeline()
        .collection("books")
        .select(arrayReverse(field("genre")).as("reversedGenres"))
        .execute()
        .get();
PipelineSnippets.java

SUM

Syntax:

sum(array: ARRAY) -> INT64 | FLOAT64

Description:

Returns the sum of all NUMERIC values in an ARRAY.

• Non-numeric values in the array are ignored.
• If any numeric value in the array is NaN, the function returns NaN.
• The return type is determined by the widest numeric type in the array: INT64 < FLOAT64.
• If 64-bit integer overflow occurs before any floating point value is summed, an error is returned. If floating point values are summed, overflow will result in +/- infinity.
• If the array contains no numeric values at all, the function returns NULL.

Examples:

array	sum(array)
[1, 2, 3]	6L
[1L, 2L, 3L]	6L
[2000000000, 2000000000]	4000000000L
[10, 20.5]	30.5
[1, "a", 2]	3L
[INT64.MAX_VALUE, 1]	error
[INT64.MAX_VALUE, 1, -1.0]	error
[INT64.MAX_VALUE, 1.0]	9.223372036854776e+18

JOIN

Syntax:

join[T <: STRING | BYTES](array: ARRAY<T>, delimiter: T) -> STRING
join[T <: STRING | BYTES](array: ARRAY<T>, delimiter: T, null_text: T) -> STRING

Description:

Returns a concatenation of the elements in array as a STRING. The array can be of STRING or BYTES data types.

• All elements in array, delimiter, and null_text must be of the same type; they must all be STRINGs or all be BYTES.
• If null_text is provided, any NULL values in array are replaced with null_text.
• If null_text is not provided, NULL values in array are omitted from the result.

Examples:

When null_text is not provided:

array	delimiter	join(array, delimiter)
["a", "b", "c"]	","	"a,b,c"
["a", null, "c"]	","	"a,c"
[b'a', b'b', b'c']	b','	b'a,b,c'
["a", b'c']	","	error
["a", "c"]	b','	error
[b'a', b'c']	","	error

When null_text is provided:

array	delimiter	null_text	join(array, delimiter, null_text)
["a", null, "c"]	","	"MISSING"	"a,MISSING,c"
[b'a', null, b'c']	b','	b'NULL'	b'a,NULL,c'
[null, "b", null]	","	"MISSING"	"MISSING,b,MISSING"
[b'a', null, null]	b','	b'NULL'	b'a,NULL,NULL'
["a", null]	","	b'N'	error
[b'a', null]	b','	"N"	error

What's next

• See the Pipeline Queries overview