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算術函式

Cloud Firestore 中的所有算術函式都具有下列行為：

如果任何輸入參數是 NULL，就會評估為 NULL。
如果任何引數是 NaN，計算結果會是 NaN。
如果發生溢位或下溢，就會產生錯誤。

此外，如果算術函式採用多個不同類型的數字引數 (例如：add(5.0, 6))，Cloud Firestore 會隱含地將引數轉換為最廣泛的輸入類型。如果只提供 INT32 輸入，傳回型別會是 INT64。

名稱	說明
`ABS`	傳回 `number` 的絕對值
`ADD`	傳回 `x + y` 的值
`SUBTRACT`	傳回 `x - y` 的值
`MULTIPLY`	傳回 `x * y` 的值
`DIVIDE`	傳回 `x / y` 的值
`MOD`	傳回 `x / y` 除以的餘數。
`CEIL`	傳回 `number` 的上限值
`FLOOR`	傳回 `number` 的底數
`ROUND`	將 `number` 四捨五入到 `places` 個小數位數
`POW`	傳回 `base^exponent` 的值
`SQRT`	傳回 `number`
`EXP`	傳回歐拉數的 `exponent` 次方
`LN`	傳回 `number` 的自然對數
`LOG`	傳回以 10 為底的`number`
`LOG10`	傳回 `number` 的對數 (以 `10` 為底)
`RAND`	傳回介於 0.0 和 1.0 之間的虛擬隨機浮點數。

ABS

語法：

abs[N <: INT32 | INT64 | FLOAT64](number: N) -> N

說明：

傳回 number 的絕對值。

如果函式會溢位 INT32 或 INT64 值，就會擲回錯誤。

範例：

數字	`abs(number)`
10	10
-10	10
10L	10L
-0.0	0.0
10.5	10.5
-10.5	10.5
-2³¹	`[error]`
-2⁶³	`[error]`

新增

語法：

add[N <: INT32 | INT64 | FLOAT64](x: N, y: N) -> N

說明：

傳回 x + y 的值。

範例：

x	年	`add(x, y)`
20	3	23
10.0	1	11.0
22.5	2.0	24.5
INT64.MAX	1	`[error]`
INT64.MIN	-1	`[error]`

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("soldBooks").add(field("unsoldBooks")).as("totalBooks"))
);test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("soldBooks").add(Field("unsoldBooks")).as("totalBooks")])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .select(Expression.add(field("soldBooks"), field("unsoldBooks")).alias("totalBooks"))
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(Expression.add(field("soldBooks"), field("unsoldBooks")).alias("totalBooks"))
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("soldBooks").add(Field.of("unsoldBooks")).as_("totalBooks"))
    .execute()
)firestore_pipelines.py

SUBTRACT

語法：

subtract[N <: INT32 | INT64 | FLOAT64](x: N, y: N) -> N

說明：

傳回 x - y 的值。

範例：

x	年	`subtract(x, y)`
20	3	17
10.0	1	9.0
22.5	2.0	20.5
INT64.MAX	-1	`[error]`
INT64.MIN	1	`[error]`

Web

const storeCredit = 7;
const result = await execute(db.pipeline()
  .collection("books")
  .select(field("price").subtract(constant(storeCredit)).as("totalCost"))
);test.firestore.js

Swift

let storeCredit = 7
let result = try await db.pipeline()
  .collection("books")
  .select([Field("price").subtract(Constant(storeCredit)).as("totalCost")])
  .execute()PipelineSnippets.swift

Kotlin

val storeCredit = 7
val result = db.pipeline()
    .collection("books")
    .select(Expression.subtract(field("price"), storeCredit).alias("totalCost"))
    .execute()DocSnippets.kt

Java

int storeCredit = 7;
Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(Expression.subtract(field("price"), storeCredit).alias("totalCost"))
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

store_credit = 7
result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("price").subtract(store_credit).as_("totalCost"))
    .execute()
)firestore_pipelines.py

MULTIPLY

語法：

multiply[N <: INT32 | INT64 | FLOAT64](x: N, y: N) -> N

說明：

傳回 x * y 的值。

範例：

x	年	`multiply(x, y)`
20	3	60
10.0	1	10.0
22.5	2.0	45.0
INT64.MAX	2	`[error]`
INT64.MIN	2	`[error]`
FLOAT64.MAX	FLOAT64.MAX	`+inf`

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("price").multiply(field("soldBooks")).as("revenue"))
);test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("price").multiply(Field("soldBooks")).as("revenue")])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .select(Expression.multiply(field("price"), field("soldBooks")).alias("revenue"))
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(Expression.multiply(field("price"), field("soldBooks")).alias("revenue"))
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("price").multiply(Field.of("soldBooks")).as_("revenue"))
    .execute()
)firestore_pipelines.py

DIVIDE

語法：

divide[N <: INT32 | INT64 | FLOAT64](x: N, y: N) -> N

說明：

傳回 x / y 的值。整數除法會截斷。

範例：

x	年	`divide(x, y)`
20	3	6
10.0	3	3.333...
22.5	2	11.25
10	0	`[error]`
1.0	0.0	`+inf`
-1.0	0.0	`-inf`

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("ratings").divide(field("soldBooks")).as("reviewRate"))
);test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("ratings").divide(Field("soldBooks")).as("reviewRate")])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .select(Expression.divide(field("ratings"), field("soldBooks")).alias("reviewRate"))
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(Expression.divide(field("ratings"), field("soldBooks")).alias("reviewRate"))
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("ratings").divide(Field.of("soldBooks")).as_("reviewRate"))
    .execute()
)firestore_pipelines.py

MOD

語法：

mod[N <: INT32 | INT64 | FLOAT64](x: N, y: N) -> N

說明：

傳回 x / y 的餘數。

如果整數型別 (INT64) 的 y 為零，則會擲回 error。
如果浮點類型 (FLOAT64) 的 y 為零，就會傳回 NaN。

範例：

x	年	`mod(x, y)`
20	3	2
-10	3	-1
10	-3	1
-10	-3	-1
10	1	0
22.5	2	0.5
22.5	0.0	`NaN`
25	0	`[error]`

Web

const displayCapacity = 1000;
const result = await execute(db.pipeline()
  .collection("books")
  .select(field("unsoldBooks").mod(constant(displayCapacity)).as("warehousedBooks"))
);test.firestore.js

Swift

let displayCapacity = 1000
let result = try await db.pipeline()
  .collection("books")
  .select([Field("unsoldBooks").mod(Constant(displayCapacity)).as("warehousedBooks")])
  .execute()PipelineSnippets.swift

Kotlin

val displayCapacity = 1000
val result = db.pipeline()
    .collection("books")
    .select(Expression.mod(field("unsoldBooks"), displayCapacity).alias("warehousedBooks"))
    .execute()DocSnippets.kt

Java

int displayCapacity = 1000;
Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(Expression.mod(field("unsoldBooks"), displayCapacity).alias("warehousedBooks"))
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

display_capacity = 1000
result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("unsoldBooks").mod(display_capacity).as_("warehousedBooks"))
    .execute()
)firestore_pipelines.py

CEIL

語法：

ceil[N <: INT32 | INT64 | FLOAT64](number: N) -> N

說明：

傳回大於或等於 number 的最小整數值。

範例：

數字	`ceil(number)`
20	20
10	10
0	0
24L	24L
-0.4	-0.0
0.4	1.0
22.5	23.0
`+inf`	`+inf`
`-inf`	`-inf`

Web

const booksPerShelf = 100;
const result = await execute(db.pipeline()
  .collection("books")
  .select(
    field("unsoldBooks").divide(constant(booksPerShelf)).ceil().as("requiredShelves")
  )
);test.firestore.js

Swift

let booksPerShelf = 100
let result = try await db.pipeline()
  .collection("books")
  .select([
    Field("unsoldBooks").divide(Constant(booksPerShelf)).ceil().as("requiredShelves")
  ])
  .execute()PipelineSnippets.swift

Kotlin

val booksPerShelf = 100
val result = db.pipeline()
    .collection("books")
    .select(
        Expression.divide(field("unsoldBooks"), booksPerShelf).ceil().alias("requiredShelves")
    )
    .execute()DocSnippets.kt

Java

int booksPerShelf = 100;
Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(
        Expression.divide(field("unsoldBooks"), booksPerShelf).ceil().alias("requiredShelves")
    )
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

books_per_shelf = 100
result = (
    client.pipeline()
    .collection("books")
    .select(
        Field.of("unsoldBooks")
        .divide(books_per_shelf)
        .ceil()
        .as_("requiredShelves")
    )
    .execute()
)firestore_pipelines.py

FLOOR

語法：

floor[N <: INT32 | INT64 | FLOAT64](number: N) -> N

說明：

傳回不大於 number 的最大整數值。

範例：

數字	`floor(number)`
20	20
10	10
0	0
2147483648	2147483648
-0.4	-1.0
0.4	0.0
22.5	22.0
`+inf`	`+inf`
`-inf`	`-inf`

Web

const result = await execute(db.pipeline()
  .collection("books")
  .addFields(
    field("wordCount").divide(field("pages")).floor().as("wordsPerPage")
  )
);test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .addFields([
    Field("wordCount").divide(Field("pages")).floor().as("wordsPerPage")
  ])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .addFields(
        Expression.divide(field("wordCount"), field("pages")).floor().alias("wordsPerPage")
    )
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .addFields(
        Expression.divide(field("wordCount"), field("pages")).floor().alias("wordsPerPage")
    )
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .add_fields(
        Field.of("wordCount").divide(Field.of("pages")).floor().as_("wordsPerPage")
    )
    .execute()
)firestore_pipelines.py

ROUND

語法：

round[N <: INT32 | INT64 | FLOAT64 | DECIMAL128](number: N) -> N
round[N <: INT32 | INT64 | FLOAT64 | DECIMAL128](number: N, places: INT64) -> N

說明：

將 places 位數的 number 捨去。如果 places 為正數，則會將小數點右側的數字進位或捨去；如果為負數，則會將小數點左側的數字進位或捨去。

如果只提供 number，則會四捨五入至最接近的整數值。
原則為四捨五入。
如果使用負數 places 值進行捨入作業時發生溢位，系統會擲回 error。

範例：

數字	地點	`round(number, places)`
15.5	0	16.0
-15.5	0	-16.0
15	1	15
15	0	15
15	-1	20
15	-2	0
15.48924	1	15.5
2³¹-1	-1	`[error]`
2⁶³-1L	-1	`[error]`

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("soldBooks").multiply(field("price")).round().as("partialRevenue"))
  .aggregate(field("partialRevenue").sum().as("totalRevenue"))
  );test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("soldBooks").multiply(Field("price")).round().as("partialRevenue")])
  .aggregate([Field("partialRevenue").sum().as("totalRevenue")])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .select(Expression.multiply(field("soldBooks"), field("price")).round().alias("partialRevenue"))
    .aggregate(AggregateFunction.sum("partialRevenue").alias("totalRevenue"))
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(Expression.multiply(field("soldBooks"), field("price")).round().alias("partialRevenue"))
    .aggregate(AggregateFunction.sum("partialRevenue").alias("totalRevenue"))
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(
        Field.of("soldBooks")
        .multiply(Field.of("price"))
        .round()
        .as_("partialRevenue")
    )
    .aggregate(Field.of("partialRevenue").sum().as_("totalRevenue"))
    .execute()
)firestore_pipelines.py

POW

語法：

pow(base: FLOAT64, exponent: FLOAT64) -> FLOAT64

說明：

傳回 base 的 exponent 次方。

如果 base <= 0 和 exponent 為負數，則會擲回錯誤。
對於任何 exponent，pow(1, exponent) 為 1。
對於任何 base，pow(base, 0) 為 1。

範例：

base	指數	`pow(base, exponent)`
2	3	8.0
2	-3	0.125
`+inf`	0	1.0
1	`+inf`	1.0
-1	0.5	`[error]`
0	-1	`[error]`

Web

const googleplex = { latitude: 37.4221, longitude: 122.0853 };
const result = await execute(db.pipeline()
  .collection("cities")
  .addFields(
    field("lat").subtract(constant(googleplex.latitude))
      .multiply(111 /* km per degree */)
      .pow(2)
      .as("latitudeDifference"),
    field("lng").subtract(constant(googleplex.longitude))
      .multiply(111 /* km per degree */)
      .pow(2)
      .as("longitudeDifference")
  )
  .select(
    field("latitudeDifference").add(field("longitudeDifference")).sqrt()
      // Inaccurate for large distances or close to poles
      .as("approximateDistanceToGoogle")
  )
);test.firestore.js

Swift

let googleplex = CLLocation(latitude: 37.4221, longitude: 122.0853)
let result = try await db.pipeline()
  .collection("cities")
  .addFields([
    Field("lat").subtract(Constant(googleplex.coordinate.latitude))
      .multiply(111 /* km per degree */)
      .pow(2)
      .as("latitudeDifference"),
    Field("lng").subtract(Constant(googleplex.coordinate.latitude))
      .multiply(111 /* km per degree */)
      .pow(2)
      .as("longitudeDifference")
  ])
  .select([
    Field("latitudeDifference").add(Field("longitudeDifference")).sqrt()
      // Inaccurate for large distances or close to poles
      .as("approximateDistanceToGoogle")
  ])
  .execute()PipelineSnippets.swift

Kotlin

val googleplex = GeoPoint(37.4221, -122.0853)
val result = db.pipeline()
    .collection("cities")
    .addFields(
        field("lat").subtract(googleplex.latitude)
            .multiply(111 /* km per degree */)
            .pow(2)
            .alias("latitudeDifference"),
        field("lng").subtract(googleplex.longitude)
            .multiply(111 /* km per degree */)
            .pow(2)
            .alias("longitudeDifference")
    )
    .select(
        field("latitudeDifference").add(field("longitudeDifference")).sqrt()
            // Inaccurate for large distances or close to poles
            .alias("approximateDistanceToGoogle")
    )
    .execute()DocSnippets.kt

Java

GeoPoint googleplex = new GeoPoint(37.4221, -122.0853);
Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("cities")
    .addFields(
        field("lat").subtract(googleplex.getLatitude())
            .multiply(111 /* km per degree */)
            .pow(2)
            .alias("latitudeDifference"),
        field("lng").subtract(googleplex.getLongitude())
            .multiply(111 /* km per degree */)
            .pow(2)
            .alias("longitudeDifference")
    )
    .select(
        field("latitudeDifference").add(field("longitudeDifference")).sqrt()
            // Inaccurate for large distances or close to poles
            .alias("approximateDistanceToGoogle")
    )
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

googleplexLat = 37.4221
googleplexLng = -122.0853
result = (
    client.pipeline()
    .collection("cities")
    .add_fields(
        Field.of("lat")
        .subtract(googleplexLat)
        .multiply(111)  # km per degree
        .pow(2)
        .as_("latitudeDifference"),
        Field.of("lng")
        .subtract(googleplexLng)
        .multiply(111)  # km per degree
        .pow(2)
        .as_("longitudeDifference"),
    )
    .select(
        Field.of("latitudeDifference")
        .add(Field.of("longitudeDifference"))
        .sqrt()
        # Inaccurate for large distances or close to poles
        .as_("approximateDistanceToGoogle")
    )
    .execute()
)firestore_pipelines.py

SQRT

語法：

sqrt[N <: FLOAT64 | DECIMAL128](number: N) -> N

說明：

傳回 number 的平方根。

如果 number 為負數，則會擲回 error。

範例：

數字	`sqrt(number)`
25	5.0
12.002	3.464...
0.0	0.0
`NaN`	`NaN`
`+inf`	`+inf`
`-inf`	`[error]`
`x < 0`	`[error]`

Web

const googleplex = { latitude: 37.4221, longitude: 122.0853 };
const result = await execute(db.pipeline()
  .collection("cities")
  .addFields(
    field("lat").subtract(constant(googleplex.latitude))
      .multiply(111 /* km per degree */)
      .pow(2)
      .as("latitudeDifference"),
    field("lng").subtract(constant(googleplex.longitude))
      .multiply(111 /* km per degree */)
      .pow(2)
      .as("longitudeDifference")
  )
  .select(
    field("latitudeDifference").add(field("longitudeDifference")).sqrt()
      // Inaccurate for large distances or close to poles
      .as("approximateDistanceToGoogle")
  )
);test.firestore.js

Swift

let googleplex = CLLocation(latitude: 37.4221, longitude: 122.0853)
let result = try await db.pipeline()
  .collection("cities")
  .addFields([
    Field("lat").subtract(Constant(googleplex.coordinate.latitude))
      .multiply(111 /* km per degree */)
      .pow(2)
      .as("latitudeDifference"),
    Field("lng").subtract(Constant(googleplex.coordinate.latitude))
      .multiply(111 /* km per degree */)
      .pow(2)
      .as("longitudeDifference")
  ])
  .select([
    Field("latitudeDifference").add(Field("longitudeDifference")).sqrt()
      // Inaccurate for large distances or close to poles
      .as("approximateDistanceToGoogle")
  ])
  .execute()PipelineSnippets.swift

Kotlin

val googleplex = GeoPoint(37.4221, -122.0853)
val result = db.pipeline()
    .collection("cities")
    .addFields(
        field("lat").subtract(googleplex.latitude)
            .multiply(111 /* km per degree */)
            .pow(2)
            .alias("latitudeDifference"),
        field("lng").subtract(googleplex.longitude)
            .multiply(111 /* km per degree */)
            .pow(2)
            .alias("longitudeDifference")
    )
    .select(
        field("latitudeDifference").add(field("longitudeDifference")).sqrt()
            // Inaccurate for large distances or close to poles
            .alias("approximateDistanceToGoogle")
    )
    .execute()DocSnippets.kt

Java

GeoPoint googleplex = new GeoPoint(37.4221, -122.0853);
Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("cities")
    .addFields(
        field("lat").subtract(googleplex.getLatitude())
            .multiply(111 /* km per degree */)
            .pow(2)
            .alias("latitudeDifference"),
        field("lng").subtract(googleplex.getLongitude())
            .multiply(111 /* km per degree */)
            .pow(2)
            .alias("longitudeDifference")
    )
    .select(
        field("latitudeDifference").add(field("longitudeDifference")).sqrt()
            // Inaccurate for large distances or close to poles
            .alias("approximateDistanceToGoogle")
    )
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

googleplexLat = 37.4221
googleplexLng = -122.0853
result = (
    client.pipeline()
    .collection("cities")
    .add_fields(
        Field.of("lat")
        .subtract(googleplexLat)
        .multiply(111)  # km per degree
        .pow(2)
        .as_("latitudeDifference"),
        Field.of("lng")
        .subtract(googleplexLng)
        .multiply(111)  # km per degree
        .pow(2)
        .as_("longitudeDifference"),
    )
    .select(
        Field.of("latitudeDifference")
        .add(Field.of("longitudeDifference"))
        .sqrt()
        # Inaccurate for large distances or close to poles
        .as_("approximateDistanceToGoogle")
    )
    .execute()
)firestore_pipelines.py

匯出

語法：

exp(exponent: FLOAT64) -> FLOAT64

說明：

傳回歐拉數的 exponent 次方值，也稱為自然指數函式。

範例：

指數	`exp(exponent)`
0.0	1.0
10	`e^10` (`FLOAT64`)
`+inf`	`+inf`
`-inf`	0

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("rating").exp().as("expRating"))
);test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("rating").exp().as("expRating")])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .select(field("rating").exp().alias("expRating"))
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("rating").exp().alias("expRating"))
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("rating").exp().as_("expRating"))
    .execute()
)firestore_pipelines.py

LN

語法：

ln(number: FLOAT64) -> FLOAT64

說明：

傳回 number 的自然對數。這個函式等同於 log(number)。

範例：

數字	`ln(number)`
1	0.0
2L	0.693...
1.0	0.0
`e` (`FLOAT64`)	1.0
`-inf`	`NaN`
`+inf`	`+inf`
`x <= 0`	`[error]`

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("rating").ln().as("lnRating"))
);test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("rating").ln().as("lnRating")])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .select(field("rating").ln().alias("lnRating"))
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("rating").ln().alias("lnRating"))
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("rating").ln().as_("lnRating"))
    .execute()
)firestore_pipelines.py

LOG

語法：

log(number: FLOAT64, base: FLOAT64) -> FLOAT64
log(number: FLOAT64) -> FLOAT64

說明：

傳回 number 的對數 (以 base 為底)。

如果只提供 number，則會傳回 number 以 base 為底的對數 (與 ln(number) 同義)。

範例：

數字	base	`log(number, base)`
100	10	2.0
`-inf`	`Numeric`	`NaN`
`Numeric`。	`+inf`	`NaN`
`number <= 0`	`Numeric`	`[error]`
`Numeric`	`base <= 0`	`[error]`
`Numeric`	1.0	`[error]`

LOG10

語法：

log10(x: FLOAT64) -> FLOAT64

說明：

傳回 number 以 10 為底的對數。

範例：

數字	`log10(number)`
100	2.0
`-inf`	`NaN`
`+inf`	`+inf`
`x <= 0`	`[error]`

RAND

語法：

rand() -> FLOAT64

說明：

Return a pseudo-random floating point number, chosen uniformly between 0.0 (inclusive) and 1.0 (exclusive).

算術函式 透過集合功能整理內容 你可以依據偏好儲存及分類內容。

算術函式

ABS

新增

Web

Swift

Kotlin

Java

Python

SUBTRACT

Web

Swift

Kotlin

Java

Python

MULTIPLY

Web

Swift

Kotlin

Java

Python

DIVIDE

Web

Swift

Kotlin

Java

Python

MOD

Web

Swift

Kotlin

Java

Python

CEIL

Web

Swift

Kotlin

Java

Python

FLOOR

Web

Swift

Kotlin

Java

Python

ROUND

Web

Swift

Kotlin

Java

Python

POW

Web

Swift

Kotlin

Java

Python

SQRT

Web

Swift

Kotlin

Java

Python

匯出

Web

Swift

Kotlin

Java

Python

LN

Web

Swift

Kotlin

Java

Python

LOG

LOG10

RAND

算術函式