Riferimento per le funzioni di confronto

Funzioni di confronto

Nome Descrizione
EQUAL Confronto di uguaglianza
GREATER_THAN Confronto maggiore di
GREATER_THAN_OR_EQUAL Confronto maggiore o uguale a
LESS_THAN Confronto con il segno "minore di"
LESS_THAN_OR_EQUAL Confronto minore o uguale
NOT_EQUAL Confronto diverso da
CMP Confronto generale

EQUAL

Sintassi:

equal(x: ANY, y: ANY) -> BOOLEAN

Esempi:

x y equal(x, y)
1L 1L TRUE
1.0 1L TRUE
-1.0 1L FALSE
NaN NaN TRUE
NULL NULL TRUE
NULL ABSENT FALSE

Descrizione:

Restituisce TRUE se x e y sono uguali, altrimenti restituisce FALSE.

Node.js
const result = await db.pipeline()
  .collection("books")
  .select(field("rating").equal(5).as("hasPerfectRating"))
  .execute();

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("rating").equal(5).as("hasPerfectRating"))
);
Swift
let result = try await db.pipeline()
  .collection("books")
  .select([Field("rating").equal(5).as("hasPerfectRating")])
  .execute()
Kotlin
Android
val result = db.pipeline()
    .collection("books")
    .select(field("rating").equal(5).alias("hasPerfectRating"))
    .execute()
Java
Android
Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("rating").equal(5).alias("hasPerfectRating"))
    .execute();
Python
from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("rating").equal(5).as_("hasPerfectRating"))
    .execute()
)
Java
Pipeline.Snapshot result =
    firestore
        .pipeline()
        .collection("books")
        .select(equal(field("rating"), 5).as("hasPerfectRating"))
        .execute()
        .get();

MAGGIORE_DI

Sintassi:

greater_than(x: ANY, y: ANY) -> BOOLEAN

Descrizione:

Restituisce TRUE se x è maggiore di y, altrimenti restituisce FALSE.

Se x e y non sono confrontabili, restituisce FALSE.

Esempi:

x y greater_than(x, y)
1L 0.0 TRUE
1L 1L FALSE
1L 2L FALSE
"foo" 0L FALSE
0L "foo" FALSE
NaN 0L FALSE
0L NaN FALSE
NULL NULL FALSE
Node.js
const result = await db.pipeline()
  .collection("books")
  .select(field("rating").greaterThan(4).as("hasHighRating"))
  .execute();

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("rating").greaterThan(4).as("hasHighRating"))
);
Swift
let result = try await db.pipeline()
  .collection("books")
  .select([Field("rating").greaterThan(4).as("hasHighRating")])
  .execute()
Kotlin
Android
val result = db.pipeline()
    .collection("books")
    .select(field("rating").greaterThan(4).alias("hasHighRating"))
    .execute()
Java
Android
Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("rating").greaterThan(4).alias("hasHighRating"))
    .execute();
Python
from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("rating").greater_than(4).as_("hasHighRating"))
    .execute()
)
Java
Pipeline.Snapshot result =
    firestore
        .pipeline()
        .collection("books")
        .select(greaterThan(field("rating"), 4).as("hasHighRating"))
        .execute()
        .get();

MAGGIORE_UGUALE

Sintassi:

greater_than_or_equal(x: ANY, y: ANY) -> BOOLEAN

Descrizione:

Restituisce TRUE se x è maggiore o uguale a y, altrimenti restituisce FALSE.

Se x e y non sono confrontabili, restituisce FALSE.

Esempi:

x y greater_than_or_equal(x, y)
1L 0.0 TRUE
1L 1L TRUE
1L 2L FALSE
"foo" 0L FALSE
0L "foo" FALSE
NaN 0L FALSE
0L NaN FALSE
NULL NULL TRUE
Node.js
const result = await db.pipeline()
  .collection("books")
  .select(field("published").greaterThanOrEqual(1900).as("publishedIn20thCentury"))
  .execute();

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("published").greaterThanOrEqual(1900).as("publishedIn20thCentury"))
);
Swift
let result = try await db.pipeline()
  .collection("books")
  .select([Field("published").greaterThanOrEqual(1900).as("publishedIn20thCentury")])
  .execute()
Kotlin
Android
val result = db.pipeline()
    .collection("books")
    .select(field("published").greaterThanOrEqual(1900).alias("publishedIn20thCentury"))
    .execute()
Java
Android
Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("published").greaterThanOrEqual(1900).alias("publishedIn20thCentury"))
    .execute();
Python
from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(
        Field.of("published")
        .greater_than_or_equal(1900)
        .as_("publishedIn20thCentury")
    )
    .execute()
)
Java
Pipeline.Snapshot result =
    firestore
        .pipeline()
        .collection("books")
        .select(greaterThanOrEqual(field("published"), 1900).as("publishedIn20thCentury"))
        .execute()
        .get();

LESS_THAN

Sintassi:

less_than(x: ANY, y: ANY) -> BOOLEAN

Descrizione:

Restituisce TRUE se x è minore di y, altrimenti restituisce FALSE.

Se x e y non sono confrontabili, restituisce FALSE.

Esempi:

x y less_than(x, y)
1L 0.0 FALSE
1L 1L FALSE
1L 2L TRUE
"foo" 0L FALSE
0L "foo" FALSE
NaN 0L FALSE
0L NaN FALSE
NULL NULL FALSE
Node.js
const result = await db.pipeline()
  .collection("books")
  .select(field("published").lessThan(1923).as("isPublicDomainProbably"))
  .execute();

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("published").lessThan(1923).as("isPublicDomainProbably"))
);
Swift
let result = try await db.pipeline()
  .collection("books")
  .select([Field("published").lessThan(1923).as("isPublicDomainProbably")])
  .execute()
Kotlin
Android
val result = db.pipeline()
    .collection("books")
    .select(field("published").lessThan(1923).alias("isPublicDomainProbably"))
    .execute()
Java
Android
Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("published").lessThan(1923).alias("isPublicDomainProbably"))
    .execute();
Python
from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("published").less_than(1923).as_("isPublicDomainProbably"))
    .execute()
)
Java
Pipeline.Snapshot result =
    firestore
        .pipeline()
        .collection("books")
        .select(lessThan(field("published"), 1923).as("isPublicDomainProbably"))
        .execute()
        .get();

LESS_THAN_OR_EQUAL

Sintassi:

less_than_or_equal(x: ANY, y: ANY) -> BOOLEAN

Descrizione:

Restituisce TRUE se x è minore o uguale a y, altrimenti restituisce FALSE.

Se x e y non sono confrontabili, restituisce FALSE.

Esempi:

x y less_than(x, y)
1L 0.0 FALSE
1L 1L TRUE
1L 2L TRUE
"foo" 0L FALSE
0L "foo" FALSE
NaN 0L FALSE
0L NaN FALSE
NULL NULL TRUE
Node.js
const result = await db.pipeline()
  .collection("books")
  .select(field("rating").lessThanOrEqual(2).as("hasBadRating"))
  .execute();

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("rating").lessThanOrEqual(2).as("hasBadRating"))
);
Swift
let result = try await db.pipeline()
  .collection("books")
  .select([Field("rating").lessThanOrEqual(2).as("hasBadRating")])
  .execute()
Kotlin
Android
val result = db.pipeline()
    .collection("books")
    .select(field("rating").lessThanOrEqual(2).alias("hasBadRating"))
    .execute()
Java
Android
Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("rating").lessThanOrEqual(2).alias("hasBadRating"))
    .execute();
Python
from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("rating").less_than_or_equal(2).as_("hasBadRating"))
    .execute()
)
Java
Pipeline.Snapshot result =
    firestore
        .pipeline()
        .collection("books")
        .select(lessThanOrEqual(field("rating"), 2).as("hasBadRating"))
        .execute()
        .get();

NOT_EQUAL

Sintassi:

not_equal(x: ANY, y: ANY) -> BOOLEAN

Descrizione:

Restituisce TRUE se x non è uguale a y, altrimenti restituisce FALSE.

Esempi:

x y not_equal(x, y)
1L 1L FALSE
1.0 1L FALSE
-1.0 1L TRUE
NaN 0L TRUE
NaN NaN FALSE
NULL NULL FALSE
NULL ABSENT TRUE
Node.js
const result = await db.pipeline()
  .collection("books")
  .select(field("title").notEqual("1984").as("not1984"))
  .execute();

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("title").notEqual("1984").as("not1984"))
);
Swift
let result = try await db.pipeline()
  .collection("books")
  .select([Field("title").notEqual("1984").as("not1984")])
  .execute()
Kotlin
Android
val result = db.pipeline()
    .collection("books")
    .select(field("title").notEqual("1984").alias("not1984"))
    .execute()
Java
Android
Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("title").notEqual("1984").alias("not1984"))
    .execute();
Python
from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("title").not_equal("1984").as_("not1984"))
    .execute()
)
Java
Pipeline.Snapshot result =
    firestore
        .pipeline()
        .collection("books")
        .select(notEqual(field("title"), "1984").as("not1984"))
        .execute()
        .get();

CMP

Sintassi:

cmp(x: ANY, y: ANY) -> Int64

Descrizione:

Confronta x e y e restituisce:

  • 1L se x è maggiore di y.
  • -1L se x è inferiore a y.
  • 0L altrimenti.

A differenza di altre funzioni di confronto, la funzione cmp(...) funziona su più tipi, seguendo lo stesso ordine utilizzato nella fase sort(...). Consulta Ordine dei tipi di valori per scoprire come vengono ordinati i valori nei vari tipi.

Esempi:

x y cmp(x, y)
1L 1L 0L
1.0 1L 0L
-1.0 1L -1L
42,5 D "foo" -1L
NULL NULL 0L
NULL ABSENT 0L

Passaggi successivi