现已推出与 MongoDB 兼容的 Cloud Firestore 企业版！了解详情。

比较函数

名称	说明
`EQUAL`	等值比较
`GREATER_THAN`	大于比较
`GREATER_THAN_OR_EQUAL`	大于或等于比较
`LESS_THAN`	小于比较
`LESS_THAN_OR_EQUAL`	小于或等于比较
`NOT_EQUAL`	不等于比较

EQUAL

语法：

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

示例：

`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`

说明：

如果 x 和 y 相等，则返回 TRUE；否则返回 FALSE。

Web

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

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("rating").equal(5).as("hasPerfectRating")])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .select(field("rating").equal(5).alias("hasPerfectRating"))
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("rating").equal(5).alias("hasPerfectRating"))
    .execute();DocSnippets.java

Python

from google.cloud.firestore_v1.pipeline_expressions import Field

result = (
    client.pipeline()
    .collection("books")
    .select(Field.of("rating").equal(5).as_("hasPerfectRating"))
    .execute()
)firestore_pipelines.py

GREATER_THAN

语法：

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

说明：

如果 x 大于 y，则返回 TRUE；否则返回 FALSE。

如果 x 和 y 不可比较，则返回 FALSE。

示例：

`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`

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("rating").greaterThan(4).as("hasHighRating"))
);test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("rating").greaterThan(4).as("hasHighRating")])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .select(field("rating").greaterThan(4).alias("hasHighRating"))
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("rating").greaterThan(4).alias("hasHighRating"))
    .execute();DocSnippets.java

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()
)firestore_pipelines.py

GREATER_THAN_OR_EQUAL

语法：

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

说明：

如果 x 大于或等于 y，则返回 TRUE；否则返回 FALSE。

如果 x 和 y 不可比较，则返回 FALSE。

示例：

`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`

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("published").greaterThanOrEqual(1900).as("publishedIn20thCentury"))
);test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("published").greaterThanOrEqual(1900).as("publishedIn20thCentury")])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .select(field("published").greaterThanOrEqual(1900).alias("publishedIn20thCentury"))
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("published").greaterThanOrEqual(1900).alias("publishedIn20thCentury"))
    .execute();DocSnippets.java

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()
)firestore_pipelines.py

LESS_THAN

语法：

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

说明：

如果 x 小于 y，则返回 TRUE；否则返回 FALSE。

如果 x 和 y 不可比较，则返回 FALSE。

示例：

`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`

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("published").lessThan(1923).as("isPublicDomainProbably"))
);test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("published").lessThan(1923).as("isPublicDomainProbably")])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .select(field("published").lessThan(1923).alias("isPublicDomainProbably"))
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("published").lessThan(1923).alias("isPublicDomainProbably"))
    .execute();DocSnippets.java

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()
)firestore_pipelines.py

LESS_THAN_OR_EQUAL

语法：

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

说明：

如果 x 小于或等于 y，则返回 TRUE；否则返回 FALSE。

如果 x 和 y 不可比较，则返回 FALSE。

示例：

`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`

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("rating").lessThanOrEqual(2).as("hasBadRating"))
);test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("rating").lessThanOrEqual(2).as("hasBadRating")])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .select(field("rating").lessThanOrEqual(2).alias("hasBadRating"))
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("rating").lessThanOrEqual(2).alias("hasBadRating"))
    .execute();DocSnippets.java

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()
)firestore_pipelines.py

NOT_EQUAL

语法：

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

说明：

如果 x 不等于 y，则返回 TRUE；否则返回 FALSE。

示例：

`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`

Web

const result = await execute(db.pipeline()
  .collection("books")
  .select(field("title").notEqual("1984").as("not1984"))
);test.firestore.js

Swift

let result = try await db.pipeline()
  .collection("books")
  .select([Field("title").notEqual("1984").as("not1984")])
  .execute()PipelineSnippets.swift

Kotlin

val result = db.pipeline()
    .collection("books")
    .select(field("title").notEqual("1984").alias("not1984"))
    .execute()DocSnippets.kt

Java

Task<Pipeline.Snapshot> result = db.pipeline()
    .collection("books")
    .select(field("title").notEqual("1984").alias("not1984"))
    .execute();DocSnippets.java

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()
)firestore_pipelines.py

比较函数 使用集合让一切井井有条 根据您的偏好保存内容并对其进行分类。

比较函数

EQUAL

Web

Swift

Kotlin

Java

Python

GREATER_THAN

Web

Swift

Kotlin

Java

Python

GREATER_THAN_OR_EQUAL

Web

Swift

Kotlin

Java

Python

LESS_THAN

Web

Swift

Kotlin

Java

Python

LESS_THAN_OR_EQUAL

Web

Swift

Kotlin

Java

Python

NOT_EQUAL

Web

Swift

Kotlin

Java

Python

比较函数