to() function
to() writes data to an InfluxDB Cloud or 2.x bucket and returns the written data.
Output data requirements
to() writes data structured using the standard InfluxDB Cloud and v2.x data
structure that includes, at a minimum, the following columns:
_time_measurement_field_value
All other columns are written to InfluxDB as tags.
Note: to() drops rows with null _time values and does not write them
to InfluxDB.
to() does not require a package import
to() is part of the influxdata/influxdb package, but is part of the
Flux prelude and does not require an import statement or package namespace.
Function type signature
(
<-tables: stream[A],
?bucket: string,
?bucketID: string,
?fieldFn: (r: A) => B,
?host: string,
?measurementColumn: string,
?org: string,
?orgID: string,
?tagColumns: [string],
?timeColumn: string,
?token: string,
) => stream[A] where A: Record, B: Record
For more information, see Function type signatures.
Parameters
bucket
Name of the bucket to write to.
bucket and bucketID are mutually exclusive.
bucketID
String-encoded bucket ID to to write to.
bucket and bucketID are mutually exclusive.
host
URL of the InfluxDB instance to write to.
See InfluxDB Cloud regions
or InfluxDB OSS URLs.
host is required when writing to a remote InfluxDB instance.
If specified, token is also required.
org
Organization name.
org and orgID are mutually exclusive.
orgID
String-encoded organization ID to query.
org and orgID are mutually exclusive.
token
InfluxDB API token.
InfluxDB 1.x or Enterprise: If authentication is disabled, provide an
empty string (""). If authentication is enabled, provide your InfluxDB
username and password using the <username>:<password> syntax.
token is required when writing to another organization or when host
is specified.
timeColumn
Time column of the output. Default is "_time".
measurementColumn
Measurement column of the output. Default is "_measurement".
tagColumns
Tag columns in the output. Defaults to all columns with type
string, excluding all value columns and columns identified by fieldFn.
fieldFn
Function that maps a field key to a field value and returns a record.
Default is (r) => ({ [r._field]: r._value }).
tables
Input data. Default is piped-forward data (<-).
Examples
- Write data to InfluxDB
- Customize measurement, tag, and field columns in the to() operation
- Write to multiple InfluxDB buckets
Write data to InfluxDB
data =
array.from(
rows: [
{
_time: 2021-01-01T00:00:00Z,
_measurement: "m",
tag1: "a",
_field: "temp",
_value: 100.1,
},
{
_time: 2021-01-01T00:01:00Z,
_measurement: "m",
tag1: "a",
_field: "temp",
_value: 99.8,
},
{
_time: 2021-01-01T00:02:00Z,
_measurement: "m",
tag1: "a",
_field: "temp",
_value: 99.1,
},
{
_time: 2021-01-01T00:03:00Z,
_measurement: "m",
tag1: "a",
_field: "temp",
_value: 98.6,
},
],
)
data
|> to(
bucket: "example-bucket",
org: "example-org",
token: "mYSuP3rSecR37t0k3N",
host: "http://localhost:8086",
)
The example above produces the following line protocol and sends it to the
InfluxDB /api/v2/write endpoint:
m,tag1=a temp=100.1 1609459200000000000
m,tag1=a temp=99.8 1609459260000000000
m,tag1=a temp=99.1 1609459320000000000
m,tag1=a temp=98.6 1609459380000000000
Customize measurement, tag, and field columns in the to() operation
data =
array.from(
rows: [
{
_time: 2021-01-01T00:00:00Z,
tag1: "a",
tag2: "b",
hum: 53.3,
temp: 100.1,
},
{
_time: 2021-01-01T00:01:00Z,
tag1: "a",
tag2: "b",
hum: 53.4,
temp: 99.8,
},
{
_time: 2021-01-01T00:02:00Z,
tag1: "a",
tag2: "b",
hum: 53.6,
temp: 99.1,
},
{
_time: 2021-01-01T00:03:00Z,
tag1: "a",
tag2: "b",
hum: 53.5,
temp: 98.6,
},
],
)
data
|> to(
bucket: "example-bucket",
measurementColumn: "tag1",
tagColumns: ["tag2"],
fieldFn: (r) => ({"hum": r.hum, "temp": r.temp}),
)
The example above produces the following line protocol and sends it to the
InfluxDB /api/v2/write endpoint:
a,tag2=b hum=53.3,temp=100.1 1609459200000000000
a,tag2=b hum=53.4,temp=99.8 1609459260000000000
a,tag2=b hum=53.6,temp=99.1 1609459320000000000
a,tag2=b hum=53.5,temp=98.6 1609459380000000000
Write to multiple InfluxDB buckets
The example below does the following:
- Writes data to
bucket1and returns the data as it is written. - Applies an empty group key to group all rows into a single table.
- Counts the number of rows.
- Maps columns required to write to InfluxDB.
- Writes the modified data to
bucket2.
data
|> to(bucket: "bucket1")
|> group()
|> count()
|> map(
fn: (r) => ({r with _time: now(), _measurement: "writeStats", _field: "numPointsWritten"}),
)
|> to(bucket: "bucket2")
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