Merge branch 'master' into jstirnaman/issue5463
Jason Stirnaman
GitHub
commit
00d16fe917
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@ -70,14 +70,19 @@
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h1 {
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@ -18,7 +18,6 @@ InfluxQL features.
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|||
|
||||
- [In-progress features](#in-progress-features)
|
||||
- [Time zones](#time-zones)
|
||||
- [Subqueries](#subqueries)
|
||||
- [SLIMIT clause](#slimit-clause)
|
||||
- [SOFFSET clause](#soffset-clause)
|
||||
- [Metaqueries](#metaqueries)
|
||||
|
|
@ -37,13 +36,6 @@ which applies a time zone offset to UTC timestamps in query results.
|
|||
|
||||
<!-- **Tracking issue**: [influxdb_iox#6933](https://github.com/influxdata/influxdb_iox/issues/6933) -->
|
||||
|
||||
### Subqueries
|
||||
|
||||
InfluxQL in {{< product-name >}} does not currently support subqueries, which
|
||||
let you query data from the results of another InfluxQL query.
|
||||
|
||||
<!-- **Tracking issue**: [influxdb_iox#6897](https://github.com/influxdata/influxdb_iox/issues/6897) -->
|
||||
|
||||
### SLIMIT clause
|
||||
|
||||
InfluxQL in {{< product-name >}} does not currently support the `SLIMIT` clause,
|
||||
|
|
|
|||
|
|
@ -66,35 +66,41 @@ It requires one or more **field expressions** and optional **tag expressions**.
|
|||
### FROM clause
|
||||
|
||||
The `FROM` clause specifies the
|
||||
[measurement](/influxdb/cloud-dedicated/reference/glossary/#measurement) to query.
|
||||
It requires one or more comma-delimited **measurement expressions**.
|
||||
[measurement](/influxdb/cloud-dedicated/reference/glossary/#measurement) or
|
||||
[subquery](/influxdb/cloud-dedicated/reference/influxql/subqueries/) to query.
|
||||
It requires one or more comma-delimited
|
||||
[measurement expressions](#measurement_expression) or [subqueries](#subquery).
|
||||
|
||||
- #### measurement_expression
|
||||
#### measurement_expression
|
||||
|
||||
Expression to identify one or more measurements to query.
|
||||
Can be a measurement name, fully-qualified measurement, constant, or
|
||||
[regular expression](/influxdb/cloud-dedicated/reference/influxql/regular-expressions/).
|
||||
A measurement expression identifies a measurement to query.
|
||||
It can be a measurement name, fully-qualified measurement, constant, or
|
||||
a [regular expression](/influxdb/cloud-dedicated/reference/influxql/regular-expressions/).
|
||||
|
||||
- ##### Measurement name
|
||||
- **Measurement name**: When using just the measurement name, InfluxQL assumes
|
||||
the default retention policy of the database specified in the query request.
|
||||
|
||||
```sql
|
||||
FROM measurement
|
||||
```
|
||||
```sql
|
||||
FROM measurement
|
||||
```
|
||||
|
||||
- ##### Fully-qualified measurement
|
||||
- **Fully-qualified measurement**: A fully qualified measurement includes a
|
||||
database name, retention policy name, and measurement name, each separated by
|
||||
a period (`.`). If the retention policy is not specified, InfluxQL uses the
|
||||
default retention policy for the specified database.
|
||||
|
||||
```sql
|
||||
FROM database.retention_policy.measurement
|
||||
```sql
|
||||
FROM database.retention_policy.measurement
|
||||
|
||||
-- Fully-qualified measurement with default retention policy
|
||||
FROM database..measurement
|
||||
```
|
||||
-- Fully-qualified measurement with default retention policy
|
||||
FROM database..measurement
|
||||
```
|
||||
|
||||
{{% note %}}
|
||||
#### InfluxDB retention policies
|
||||
{{% note %}}
|
||||
#### InfluxQL retention policies
|
||||
|
||||
In {{< product-name >}}, **retention policies** are not part of the data model like
|
||||
they are in InfluxDB 1.x.
|
||||
In {{< product-name >}}, **retention policies** are not part of the data model
|
||||
like they are in InfluxDB 1.x.
|
||||
Each {{< product-name >}} database has a **retention period** which defines the
|
||||
maximum age of data to retain in the database. To use fully-qualified
|
||||
measurements in InfluxQL queries, use the following naming convention when
|
||||
|
|
@ -103,7 +109,14 @@ measurements in InfluxQL queries, use the following naming convention when
|
|||
```
|
||||
database_name/retention_policy
|
||||
```
|
||||
{{% /note %}}
|
||||
{{% /note %}}
|
||||
|
||||
#### Subquery
|
||||
|
||||
An InfluxQL subquery is a query nested in the `FROM` clause of an InfluxQL query.
|
||||
The outer query queries results returned by the inner query (subquery).
|
||||
|
||||
For more information, see [InfluxQL subqueries](/influxdb/cloud-dedicated/reference/influxql/subqueries/).
|
||||
|
||||
## Notable SELECT statement behaviors
|
||||
|
||||
|
|
|
|||
|
|
@ -0,0 +1,246 @@
|
|||
---
|
||||
title: InfluxQL subqueries
|
||||
description: >
|
||||
An InfluxQL subquery is a query nested in the `FROM` clause of an InfluxQL query.
|
||||
The outer query queries results returned by the inner query (subquery).
|
||||
menu:
|
||||
influxdb_cloud_dedicated:
|
||||
name: Subqueries
|
||||
identifier: influxql-subqueries
|
||||
parent: influxql-reference
|
||||
weight: 207
|
||||
list_code_example: |
|
||||
```sql
|
||||
SELECT_clause FROM ( SELECT_statement ) [...]
|
||||
```
|
||||
---
|
||||
|
||||
An InfluxQL subquery is a query nested in the `FROM` clause of an InfluxQL query.
|
||||
The outer query queries results returned by the inner query (subquery).
|
||||
|
||||
- [Syntax](#syntax)
|
||||
- [Examples](#examples)
|
||||
- [Notable subquery behaviors](#notable-subquery-behaviors)
|
||||
|
||||
{{% note %}}
|
||||
InfluxQL does not support a `HAVING` clause, however InfluxQL subqueries offer
|
||||
functionality similar to the [SQL `HAVING` clause](/influxdb/cloud-dedicated/reference/sql/having/).
|
||||
{{% /note %}}
|
||||
|
||||
## Syntax
|
||||
|
||||
```sql
|
||||
SELECT_clause FROM ( SELECT_statement ) [...]
|
||||
```
|
||||
|
||||
When using subqueries, InfluxQL **performs the inner query first**, then performs
|
||||
the outer query.
|
||||
|
||||
The outer query requires a [`SELECT` clause](/influxdb/cloud-dedicated/reference/influxql/select/#select-clause)
|
||||
and a [`FROM` clause](/influxdb/cloud-dedicated/reference/influxql/select/#from-clause).
|
||||
The inner query is enclosed in parentheses in the outer query's `FROM` clause.
|
||||
|
||||
InfluxQL supports multiple nested subqueries:
|
||||
|
||||
```sql
|
||||
SELECT_clause FROM ( SELECT_clause FROM ( SELECT_statement ) [...] ) [...]
|
||||
```
|
||||
|
||||
## Examples
|
||||
|
||||
{{% note %}}
|
||||
#### Sample data
|
||||
|
||||
The examples below use the following sample data sets:
|
||||
|
||||
- [Get started home sensor data](/influxdb/cloud-dedicated/reference/sample-data/#get-started-home-sensor-data)
|
||||
- [Random numbers sample data](/influxdb/cloud-dedicated/reference/sample-data/#random-numbers-sample-data)
|
||||
{{% /note %}}
|
||||
|
||||
{{< expand-wrapper >}}
|
||||
|
||||
{{% expand "Apply an aggregate function to an aggregated result set" %}}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
SUM(max)
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
MAX(temp)
|
||||
FROM
|
||||
home
|
||||
GROUP BY
|
||||
room
|
||||
)
|
||||
```
|
||||
|
||||
{{% influxql/table-meta %}}
|
||||
Table: home
|
||||
{{% /influxql/table-meta %}}
|
||||
|
||||
| time | sum |
|
||||
| :------------------- | ---: |
|
||||
| 1970-01-01T00:00:00Z | 46.1 |
|
||||
|
||||
{{% /expand %}}
|
||||
|
||||
{{% expand "Calculate the average difference between two fields" %}}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
MEAN(difference)
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
a - b AS difference
|
||||
FROM
|
||||
numbers
|
||||
)
|
||||
```
|
||||
|
||||
{{% influxql/table-meta %}}
|
||||
Table: numbers
|
||||
{{% /influxql/table-meta %}}
|
||||
|
||||
| time | mean |
|
||||
| :------------------- | -------------------: |
|
||||
| 1970-01-01T00:00:00Z | -0.03629771779732732 |
|
||||
|
||||
{{% /expand %}}
|
||||
|
||||
{{% expand "Filter aggregate values based on a threshold" %}}
|
||||
{{% influxdb/custom-timestamps %}}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
co_change
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
SPREAD(co) AS co_change
|
||||
FROM
|
||||
home
|
||||
GROUP BY
|
||||
room,
|
||||
time(2h)
|
||||
)
|
||||
WHERE
|
||||
time >= '2022-01-01T08:00:00Z'
|
||||
AND time <= '2022-01-01T20:00:00Z'
|
||||
AND co_change >= 4
|
||||
```
|
||||
|
||||
{{% influxql/table-meta %}}
|
||||
Table: home
|
||||
{{% /influxql/table-meta %}}
|
||||
|
||||
| time | co_chnage |
|
||||
| :------------------- | --------: |
|
||||
| 2022-01-01T18:00:00Z | 4 |
|
||||
| 2022-01-01T18:00:00Z | 5 |
|
||||
|
||||
{{% /influxdb/custom-timestamps %}}
|
||||
{{% /expand %}}
|
||||
|
||||
{{% expand "Perform additional aggregate operations on aggregate values" %}}
|
||||
{{% influxdb/custom-timestamps %}}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
SUM(co_derivative) AS sum_derivative
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
DERIVATIVE(MEAN(co)) AS co_derivative
|
||||
FROM
|
||||
home
|
||||
GROUP BY
|
||||
time(12m),
|
||||
room
|
||||
)
|
||||
WHERE
|
||||
time >= '2022-01-01T08:00:00Z'
|
||||
AND time <= '2022-01-01T20:00:00Z'
|
||||
GROUP BY
|
||||
room
|
||||
```
|
||||
|
||||
{{% /influxdb/custom-timestamps %}}
|
||||
|
||||
{{% influxql/table-meta %}}
|
||||
Table: home
|
||||
{{% /influxql/table-meta %}}
|
||||
|
||||
| time | room | sum_derivative |
|
||||
| :------------------- | :---------- | -------------: |
|
||||
| 1970-01-01T00:00:00Z | Kitchen | 5.2 |
|
||||
| 1970-01-01T00:00:00Z | Living Room | 3.4 |
|
||||
|
||||
{{% /expand %}}
|
||||
{{< /expand-wrapper >}}
|
||||
|
||||
## Notable subquery behaviors
|
||||
|
||||
- [Apply time bounds to the outer query to improve performance](#apply-time-bounds-to-the-outer-query-to-improve-performance)
|
||||
- [Cannot use multiple SELECT statements in a subquery](#cannot-use-multiple-select-statements-in-a-subquery)
|
||||
|
||||
### Apply time bounds to the outer query to improve performance
|
||||
|
||||
To improve the performance of InfluxQL queries that use subqueries and a
|
||||
specified time range, apply the `WHERE` clause with time-based predicates to the
|
||||
outer query rather than the inner query.
|
||||
For example--the following queries return the same results, but **the query with
|
||||
time-based predicate on the outer query is more performant than the query with
|
||||
time-based predicate on the inner query**:
|
||||
|
||||
{{% influxdb/custom-timestamps %}}
|
||||
|
||||
#### Time bounds on the outer query {note="(Recommended)"}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
inner_value AS value
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
raw_value as inner_value
|
||||
)
|
||||
WHERE
|
||||
time >= '2022-01-01T08:00:00Z'
|
||||
AND time <= '2022-01-01T20:00:00Z'
|
||||
```
|
||||
|
||||
#### Time bounds on the inner query
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
inner_value AS value
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
raw_value as inner_value
|
||||
WHERE
|
||||
time >= '2022-07-19T08:00:00Z'
|
||||
AND time <= '2022-01-01T20:00:00Z'
|
||||
)
|
||||
```
|
||||
{{% /influxdb/custom-timestamps %}}
|
||||
|
||||
### Cannot use multiple SELECT statements in a subquery
|
||||
|
||||
InfluxQL does not support multiple
|
||||
[`SELECT` statements](/influxdb/cloud-dedicated/reference/influxql/select/)
|
||||
per subquery:
|
||||
|
||||
```sql
|
||||
SELECT_clause FROM (SELECT_statement; SELECT_statement) [...]
|
||||
```
|
||||
|
||||
However, InfluxQL does support multiple nested subqueries per outer query:
|
||||
|
||||
```sql
|
||||
SELECT_clause FROM ( SELECT_clause FROM ( SELECT_statement ) [...] ) [...]
|
||||
------------------ ----------------
|
||||
Subquery 1 Subquery 2
|
||||
```
|
||||
|
|
@ -18,7 +18,6 @@ InfluxQL features.
|
|||
|
||||
- [In-progress features](#in-progress-features)
|
||||
- [Time zones](#time-zones)
|
||||
- [Subqueries](#subqueries)
|
||||
- [SLIMIT clause](#slimit-clause)
|
||||
- [SOFFSET clause](#soffset-clause)
|
||||
- [Metaqueries](#metaqueries)
|
||||
|
|
@ -37,13 +36,6 @@ which applies a time zone offset to UTC timestamps in query results.
|
|||
|
||||
<!-- **Tracking issue**: [influxdb_iox#6933](https://github.com/influxdata/influxdb_iox/issues/6933) -->
|
||||
|
||||
### Subqueries
|
||||
|
||||
InfluxQL in {{< product-name >}} does not currently support subqueries, which
|
||||
let you query data from the results of another InfluxQL query.
|
||||
|
||||
<!-- **Tracking issue**: [influxdb_iox#6897](https://github.com/influxdata/influxdb_iox/issues/6897) -->
|
||||
|
||||
### SLIMIT clause
|
||||
|
||||
InfluxQL in {{< product-name >}} does not currently support the `SLIMIT` clause,
|
||||
|
|
|
|||
|
|
@ -66,44 +66,57 @@ It requires one or more **field expressions** and optional **tag expressions**.
|
|||
### FROM clause
|
||||
|
||||
The `FROM` clause specifies the
|
||||
[measurement](/influxdb/cloud-serverless/reference/glossary/#measurement) to query.
|
||||
It requires one or more comma-delimited [measurement_expressions](#measurement_expression).
|
||||
[measurement](/influxdb/cloud-serverless/reference/glossary/#measurement) or
|
||||
[subquery](/influxdb/cloud-serverless/reference/influxql/subqueries/) to query.
|
||||
It requires one or more comma-delimited
|
||||
[measurement expressions](#measurement_expression) or [subqueries](#subquery).
|
||||
|
||||
- #### measurement_expression
|
||||
#### measurement_expression
|
||||
|
||||
Expression to identify one or more measurements to query.
|
||||
Can be a measurement name, fully-qualified measurement, constant, or
|
||||
[regular expression](/influxdb/cloud-serverless/reference/influxql/regular-expressions/).
|
||||
A measurement expression identifies a measurement to query.
|
||||
It can be a measurement name, fully-qualified measurement, constant, or
|
||||
a [regular expression](/influxdb/cloud-serverless/reference/influxql/regular-expressions/).
|
||||
|
||||
- ##### Measurement name
|
||||
- **Measurement name**: When using just the measurement name, InfluxQL assumes
|
||||
the default retention policy of the database specified in the query request.
|
||||
|
||||
```sql
|
||||
FROM measurement
|
||||
```
|
||||
```sql
|
||||
FROM measurement
|
||||
```
|
||||
|
||||
- ##### Fully-qualified measurement
|
||||
- **Fully-qualified measurement**: A fully qualified measurement includes a
|
||||
database name, retention policy name, and measurement name, each separated by
|
||||
a period (`.`). If the retention policy is not specified, InfluxQL uses the
|
||||
default retention policy for the specified database.
|
||||
|
||||
```sql
|
||||
FROM database.retention_policy.measurement
|
||||
```sql
|
||||
FROM database.retention_policy.measurement
|
||||
|
||||
-- Fully-qualified measurement with default retention policy
|
||||
FROM database..measurement
|
||||
```
|
||||
-- Fully-qualified measurement with default retention policy
|
||||
FROM database..measurement
|
||||
```
|
||||
|
||||
{{% note %}}
|
||||
#### InfluxDB retention policies
|
||||
{{% note %}}
|
||||
#### InfluxQL retention policies
|
||||
|
||||
In {{< product-name >}}, **retention policies** are not part of the data model like
|
||||
they are in InfluxDB 1.x.
|
||||
Each {{< product-name >}} bucket has a **retention period** which defines the
|
||||
maximum age of data to retain in the bucket. To use fully-qualified
|
||||
In {{< product-name >}}, **retention policies** are not part of the data model
|
||||
like they are in InfluxDB 1.x.
|
||||
Each {{< product-name >}} database has a **retention period** which defines the
|
||||
maximum age of data to retain in the database. To use fully-qualified
|
||||
measurements in InfluxQL queries, use the following naming convention when
|
||||
[creating a bucket](/influxdb/cloud-serverless/admin/buckets/create-bucket/):
|
||||
[creating a database](/influxdb/cloud-serverless/admin/databases/create/):
|
||||
|
||||
```
|
||||
database_name/retention_policy
|
||||
```
|
||||
{{% /note %}}
|
||||
{{% /note %}}
|
||||
|
||||
#### Subquery
|
||||
|
||||
An InfluxQL subquery is a query nested in the `FROM` clause of an InfluxQL query.
|
||||
The outer query queries results returned by the inner query (subquery).
|
||||
|
||||
For more information, see [InfluxQL subqueries](/influxdb/cloud-serverless/reference/influxql/subqueries/).
|
||||
|
||||
## Notable SELECT statement behaviors
|
||||
|
||||
|
|
|
|||
|
|
@ -0,0 +1,246 @@
|
|||
---
|
||||
title: InfluxQL subqueries
|
||||
description: >
|
||||
An InfluxQL subquery is a query nested in the `FROM` clause of an InfluxQL query.
|
||||
The outer query queries results returned by the inner query (subquery).
|
||||
menu:
|
||||
influxdb_cloud_serverless:
|
||||
name: Subqueries
|
||||
identifier: influxql-subqueries
|
||||
parent: influxql-reference
|
||||
weight: 207
|
||||
list_code_example: |
|
||||
```sql
|
||||
SELECT_clause FROM ( SELECT_statement ) [...]
|
||||
```
|
||||
---
|
||||
|
||||
An InfluxQL subquery is a query nested in the `FROM` clause of an InfluxQL query.
|
||||
The outer query queries results returned by the inner query (subquery).
|
||||
|
||||
- [Syntax](#syntax)
|
||||
- [Examples](#examples)
|
||||
- [Notable subquery behaviors](#notable-subquery-behaviors)
|
||||
|
||||
{{% note %}}
|
||||
InfluxQL does not support a `HAVING` clause, however InfluxQL subqueries offer
|
||||
functionality similar to the [SQL `HAVING` clause](/influxdb/cloud-serverless/reference/sql/having/).
|
||||
{{% /note %}}
|
||||
|
||||
## Syntax
|
||||
|
||||
```sql
|
||||
SELECT_clause FROM ( SELECT_statement ) [...]
|
||||
```
|
||||
|
||||
When using subqueries, InfluxQL **performs the inner query first**, then performs
|
||||
the outer query.
|
||||
|
||||
The outer query requires a [`SELECT` clause](/influxdb/cloud-serverless/reference/influxql/select/#select-clause)
|
||||
and a [`FROM` clause](/influxdb/cloud-serverless/reference/influxql/select/#from-clause).
|
||||
The inner query is enclosed in parentheses in the outer query's `FROM` clause.
|
||||
|
||||
InfluxQL supports multiple nested subqueries:
|
||||
|
||||
```sql
|
||||
SELECT_clause FROM ( SELECT_clause FROM ( SELECT_statement ) [...] ) [...]
|
||||
```
|
||||
|
||||
## Examples
|
||||
|
||||
{{% note %}}
|
||||
#### Sample data
|
||||
|
||||
The examples below use the following sample data sets:
|
||||
|
||||
- [Get started home sensor data](/influxdb/cloud-serverless/reference/sample-data/#get-started-home-sensor-data)
|
||||
- [Random numbers sample data](/influxdb/cloud-serverless/reference/sample-data/#random-numbers-sample-data)
|
||||
{{% /note %}}
|
||||
|
||||
{{< expand-wrapper >}}
|
||||
|
||||
{{% expand "Apply an aggregate function to an aggregated result set" %}}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
SUM(max)
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
MAX(temp)
|
||||
FROM
|
||||
home
|
||||
GROUP BY
|
||||
room
|
||||
)
|
||||
```
|
||||
|
||||
{{% influxql/table-meta %}}
|
||||
Table: home
|
||||
{{% /influxql/table-meta %}}
|
||||
|
||||
| time | sum |
|
||||
| :------------------- | ---: |
|
||||
| 1970-01-01T00:00:00Z | 46.1 |
|
||||
|
||||
{{% /expand %}}
|
||||
|
||||
{{% expand "Calculate the average difference between two fields" %}}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
MEAN(difference)
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
a - b AS difference
|
||||
FROM
|
||||
numbers
|
||||
)
|
||||
```
|
||||
|
||||
{{% influxql/table-meta %}}
|
||||
Table: numbers
|
||||
{{% /influxql/table-meta %}}
|
||||
|
||||
| time | mean |
|
||||
| :------------------- | -------------------: |
|
||||
| 1970-01-01T00:00:00Z | -0.03629771779732732 |
|
||||
|
||||
{{% /expand %}}
|
||||
|
||||
{{% expand "Filter aggregate values based on a threshold" %}}
|
||||
{{% influxdb/custom-timestamps %}}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
co_change
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
SPREAD(co) AS co_change
|
||||
FROM
|
||||
home
|
||||
GROUP BY
|
||||
room,
|
||||
time(2h)
|
||||
)
|
||||
WHERE
|
||||
time >= '2022-01-01T08:00:00Z'
|
||||
AND time <= '2022-01-01T20:00:00Z'
|
||||
AND co_change >= 4
|
||||
```
|
||||
|
||||
{{% influxql/table-meta %}}
|
||||
Table: home
|
||||
{{% /influxql/table-meta %}}
|
||||
|
||||
| time | co_chnage |
|
||||
| :------------------- | --------: |
|
||||
| 2022-01-01T18:00:00Z | 4 |
|
||||
| 2022-01-01T18:00:00Z | 5 |
|
||||
|
||||
{{% /influxdb/custom-timestamps %}}
|
||||
{{% /expand %}}
|
||||
|
||||
{{% expand "Perform additional aggregate operations on aggregate values" %}}
|
||||
{{% influxdb/custom-timestamps %}}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
SUM(co_derivative) AS sum_derivative
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
DERIVATIVE(MEAN(co)) AS co_derivative
|
||||
FROM
|
||||
home
|
||||
GROUP BY
|
||||
time(12m),
|
||||
room
|
||||
)
|
||||
WHERE
|
||||
time >= '2022-01-01T08:00:00Z'
|
||||
AND time <= '2022-01-01T20:00:00Z'
|
||||
GROUP BY
|
||||
room
|
||||
```
|
||||
|
||||
{{% /influxdb/custom-timestamps %}}
|
||||
|
||||
{{% influxql/table-meta %}}
|
||||
Table: home
|
||||
{{% /influxql/table-meta %}}
|
||||
|
||||
| time | room | sum_derivative |
|
||||
| :------------------- | :---------- | -------------: |
|
||||
| 1970-01-01T00:00:00Z | Kitchen | 5.2 |
|
||||
| 1970-01-01T00:00:00Z | Living Room | 3.4 |
|
||||
|
||||
{{% /expand %}}
|
||||
{{< /expand-wrapper >}}
|
||||
|
||||
## Notable subquery behaviors
|
||||
|
||||
- [Apply time bounds to the outer query to improve performance](#apply-time-bounds-to-the-outer-query-to-improve-performance)
|
||||
- [Cannot use multiple SELECT statements in a subquery](#cannot-use-multiple-select-statements-in-a-subquery)
|
||||
|
||||
### Apply time bounds to the outer query to improve performance
|
||||
|
||||
To improve the performance of InfluxQL queries that use subqueries and a
|
||||
specified time range, apply the `WHERE` clause with time-based predicates to the
|
||||
outer query rather than the inner query.
|
||||
For example--the following queries return the same results, but **the query with
|
||||
time-based predicate on the outer query is more performant than the query with
|
||||
time-based predicate on the inner query**:
|
||||
|
||||
{{% influxdb/custom-timestamps %}}
|
||||
|
||||
#### Time bounds on the outer query {note="(Recommended)"}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
inner_value AS value
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
raw_value as inner_value
|
||||
)
|
||||
WHERE
|
||||
time >= '2022-01-01T08:00:00Z'
|
||||
AND time <= '2022-01-01T20:00:00Z'
|
||||
```
|
||||
|
||||
#### Time bounds on the inner query
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
inner_value AS value
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
raw_value as inner_value
|
||||
WHERE
|
||||
time >= '2022-07-19T08:00:00Z'
|
||||
AND time <= '2022-01-01T20:00:00Z'
|
||||
)
|
||||
```
|
||||
{{% /influxdb/custom-timestamps %}}
|
||||
|
||||
### Cannot use multiple SELECT statements in a subquery
|
||||
|
||||
InfluxQL does not support multiple
|
||||
[`SELECT` statements](/influxdb/cloud-serverless/reference/influxql/select/)
|
||||
per subquery:
|
||||
|
||||
```sql
|
||||
SELECT_clause FROM (SELECT_statement; SELECT_statement) [...]
|
||||
```
|
||||
|
||||
However, InfluxQL does support multiple nested subqueries per outer query:
|
||||
|
||||
```sql
|
||||
SELECT_clause FROM ( SELECT_clause FROM ( SELECT_statement ) [...] ) [...]
|
||||
------------------ ----------------
|
||||
Subquery 1 Subquery 2
|
||||
```
|
||||
|
|
@ -18,7 +18,6 @@ InfluxQL features.
|
|||
|
||||
- [In-progress features](#in-progress-features)
|
||||
- [Time zones](#time-zones)
|
||||
- [Subqueries](#subqueries)
|
||||
- [SLIMIT clause](#slimit-clause)
|
||||
- [SOFFSET clause](#soffset-clause)
|
||||
- [Metaqueries](#metaqueries)
|
||||
|
|
@ -37,13 +36,6 @@ which applies a time zone offset to UTC timestamps in query results.
|
|||
|
||||
<!-- **Tracking issue**: [influxdb_iox#6933](https://github.com/influxdata/influxdb_iox/issues/6933) -->
|
||||
|
||||
### Subqueries
|
||||
|
||||
InfluxQL in {{< product-name >}} does not currently support subqueries, which
|
||||
let you query data from the results of another InfluxQL query.
|
||||
|
||||
<!-- **Tracking issue**: [influxdb_iox#6897](https://github.com/influxdata/influxdb_iox/issues/6897) -->
|
||||
|
||||
### SLIMIT clause
|
||||
|
||||
InfluxQL in {{< product-name >}} does not currently support the `SLIMIT` clause,
|
||||
|
|
|
|||
|
|
@ -66,35 +66,41 @@ It requires one or more **field expressions** and optional **tag expressions**.
|
|||
### FROM clause
|
||||
|
||||
The `FROM` clause specifies the
|
||||
[measurement](/influxdb/clustered/reference/glossary/#measurement) to query.
|
||||
It requires one or more comma-delimited **measurement expressions**.
|
||||
[measurement](/influxdb/clustered/reference/glossary/#measurement) or
|
||||
[subquery](/influxdb/clustered/reference/influxql/subqueries/) to query.
|
||||
It requires one or more comma-delimited
|
||||
[measurement expressions](#measurement_expression) or [subqueries](#subquery).
|
||||
|
||||
- #### measurement_expression
|
||||
#### measurement_expression
|
||||
|
||||
Expression to identify one or more measurements to query.
|
||||
Can be a measurement name, fully-qualified measurement, constant, or
|
||||
[regular expression](/influxdb/clustered/reference/influxql/regular-expressions/).
|
||||
A measurement expression identifies a measurement to query.
|
||||
It can be a measurement name, fully-qualified measurement, constant, or
|
||||
a [regular expression](/influxdb/clustered/reference/influxql/regular-expressions/).
|
||||
|
||||
- ##### Measurement name
|
||||
- **Measurement name**: When using just the measurement name, InfluxQL assumes
|
||||
the default retention policy of the database specified in the query request.
|
||||
|
||||
```sql
|
||||
FROM measurement
|
||||
```
|
||||
```sql
|
||||
FROM measurement
|
||||
```
|
||||
|
||||
- ##### Fully-qualified measurement
|
||||
- **Fully-qualified measurement**: A fully qualified measurement includes a
|
||||
database name, retention policy name, and measurement name, each separated by
|
||||
a period (`.`). If the retention policy is not specified, InfluxQL uses the
|
||||
default retention policy for the specified database.
|
||||
|
||||
```sql
|
||||
FROM database.retention_policy.measurement
|
||||
```sql
|
||||
FROM database.retention_policy.measurement
|
||||
|
||||
-- Fully-qualified measurement with default retention policy
|
||||
FROM database..measurement
|
||||
```
|
||||
-- Fully-qualified measurement with default retention policy
|
||||
FROM database..measurement
|
||||
```
|
||||
|
||||
{{% note %}}
|
||||
#### InfluxDB retention policies
|
||||
{{% note %}}
|
||||
#### InfluxQL retention policies
|
||||
|
||||
In {{< product-name >}}, **retention policies** are not part of the data model like
|
||||
they are in InfluxDB 1.x.
|
||||
In {{< product-name >}}, **retention policies** are not part of the data model
|
||||
like they are in InfluxDB 1.x.
|
||||
Each {{< product-name >}} database has a **retention period** which defines the
|
||||
maximum age of data to retain in the database. To use fully-qualified
|
||||
measurements in InfluxQL queries, use the following naming convention when
|
||||
|
|
@ -103,7 +109,14 @@ measurements in InfluxQL queries, use the following naming convention when
|
|||
```
|
||||
database_name/retention_policy
|
||||
```
|
||||
{{% /note %}}
|
||||
{{% /note %}}
|
||||
|
||||
#### Subquery
|
||||
|
||||
An InfluxQL subquery is a query nested in the `FROM` clause of an InfluxQL query.
|
||||
The outer query queries results returned by the inner query (subquery).
|
||||
|
||||
For more information, see [InfluxQL subqueries](/influxdb/clustered/reference/influxql/subqueries/).
|
||||
|
||||
## Notable SELECT statement behaviors
|
||||
|
||||
|
|
|
|||
|
|
@ -0,0 +1,246 @@
|
|||
---
|
||||
title: InfluxQL subqueries
|
||||
description: >
|
||||
An InfluxQL subquery is a query nested in the `FROM` clause of an InfluxQL query.
|
||||
The outer query queries results returned by the inner query (subquery).
|
||||
menu:
|
||||
influxdb_clustered:
|
||||
name: Subqueries
|
||||
identifier: influxql-subqueries
|
||||
parent: influxql-reference
|
||||
weight: 207
|
||||
list_code_example: |
|
||||
```sql
|
||||
SELECT_clause FROM ( SELECT_statement ) [...]
|
||||
```
|
||||
---
|
||||
|
||||
An InfluxQL subquery is a query nested in the `FROM` clause of an InfluxQL query.
|
||||
The outer query queries results returned by the inner query (subquery).
|
||||
|
||||
- [Syntax](#syntax)
|
||||
- [Examples](#examples)
|
||||
- [Notable subquery behaviors](#notable-subquery-behaviors)
|
||||
|
||||
{{% note %}}
|
||||
InfluxQL does not support a `HAVING` clause, however InfluxQL subqueries offer
|
||||
functionality similar to the [SQL `HAVING` clause](/influxdb/clustered/reference/sql/having/).
|
||||
{{% /note %}}
|
||||
|
||||
## Syntax
|
||||
|
||||
```sql
|
||||
SELECT_clause FROM ( SELECT_statement ) [...]
|
||||
```
|
||||
|
||||
When using subqueries, InfluxQL **performs the inner query first**, then performs
|
||||
the outer query.
|
||||
|
||||
The outer query requires a [`SELECT` clause](/influxdb/clustered/reference/influxql/select/#select-clause)
|
||||
and a [`FROM` clause](/influxdb/clustered/reference/influxql/select/#from-clause).
|
||||
The inner query is enclosed in parentheses in the outer query's `FROM` clause.
|
||||
|
||||
InfluxQL supports multiple nested subqueries:
|
||||
|
||||
```sql
|
||||
SELECT_clause FROM ( SELECT_clause FROM ( SELECT_statement ) [...] ) [...]
|
||||
```
|
||||
|
||||
## Examples
|
||||
|
||||
{{% note %}}
|
||||
#### Sample data
|
||||
|
||||
The examples below use the following sample data sets:
|
||||
|
||||
- [Get started home sensor data](/influxdb/clustered/reference/sample-data/#get-started-home-sensor-data)
|
||||
- [Random numbers sample data](/influxdb/clustered/reference/sample-data/#random-numbers-sample-data)
|
||||
{{% /note %}}
|
||||
|
||||
{{< expand-wrapper >}}
|
||||
|
||||
{{% expand "Apply an aggregate function to an aggregated result set" %}}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
SUM(max)
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
MAX(temp)
|
||||
FROM
|
||||
home
|
||||
GROUP BY
|
||||
room
|
||||
)
|
||||
```
|
||||
|
||||
{{% influxql/table-meta %}}
|
||||
Table: home
|
||||
{{% /influxql/table-meta %}}
|
||||
|
||||
| time | sum |
|
||||
| :------------------- | ---: |
|
||||
| 1970-01-01T00:00:00Z | 46.1 |
|
||||
|
||||
{{% /expand %}}
|
||||
|
||||
{{% expand "Calculate the average difference between two fields" %}}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
MEAN(difference)
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
a - b AS difference
|
||||
FROM
|
||||
numbers
|
||||
)
|
||||
```
|
||||
|
||||
{{% influxql/table-meta %}}
|
||||
Table: numbers
|
||||
{{% /influxql/table-meta %}}
|
||||
|
||||
| time | mean |
|
||||
| :------------------- | -------------------: |
|
||||
| 1970-01-01T00:00:00Z | -0.03629771779732732 |
|
||||
|
||||
{{% /expand %}}
|
||||
|
||||
{{% expand "Filter aggregate values based on a threshold" %}}
|
||||
{{% influxdb/custom-timestamps %}}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
co_change
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
SPREAD(co) AS co_change
|
||||
FROM
|
||||
home
|
||||
GROUP BY
|
||||
room,
|
||||
time(2h)
|
||||
)
|
||||
WHERE
|
||||
time >= '2022-01-01T08:00:00Z'
|
||||
AND time <= '2022-01-01T20:00:00Z'
|
||||
AND co_change >= 4
|
||||
```
|
||||
|
||||
{{% influxql/table-meta %}}
|
||||
Table: home
|
||||
{{% /influxql/table-meta %}}
|
||||
|
||||
| time | co_chnage |
|
||||
| :------------------- | --------: |
|
||||
| 2022-01-01T18:00:00Z | 4 |
|
||||
| 2022-01-01T18:00:00Z | 5 |
|
||||
|
||||
{{% /influxdb/custom-timestamps %}}
|
||||
{{% /expand %}}
|
||||
|
||||
{{% expand "Perform additional aggregate operations on aggregate values" %}}
|
||||
{{% influxdb/custom-timestamps %}}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
SUM(co_derivative) AS sum_derivative
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
DERIVATIVE(MEAN(co)) AS co_derivative
|
||||
FROM
|
||||
home
|
||||
GROUP BY
|
||||
time(12m),
|
||||
room
|
||||
)
|
||||
WHERE
|
||||
time >= '2022-01-01T08:00:00Z'
|
||||
AND time <= '2022-01-01T20:00:00Z'
|
||||
GROUP BY
|
||||
room
|
||||
```
|
||||
|
||||
{{% /influxdb/custom-timestamps %}}
|
||||
|
||||
{{% influxql/table-meta %}}
|
||||
Table: home
|
||||
{{% /influxql/table-meta %}}
|
||||
|
||||
| time | room | sum_derivative |
|
||||
| :------------------- | :---------- | -------------: |
|
||||
| 1970-01-01T00:00:00Z | Kitchen | 5.2 |
|
||||
| 1970-01-01T00:00:00Z | Living Room | 3.4 |
|
||||
|
||||
{{% /expand %}}
|
||||
{{< /expand-wrapper >}}
|
||||
|
||||
## Notable subquery behaviors
|
||||
|
||||
- [Apply time bounds to the outer query to improve performance](#apply-time-bounds-to-the-outer-query-to-improve-performance)
|
||||
- [Cannot use multiple SELECT statements in a subquery](#cannot-use-multiple-select-statements-in-a-subquery)
|
||||
|
||||
### Apply time bounds to the outer query to improve performance
|
||||
|
||||
To improve the performance of InfluxQL queries that use subqueries and a
|
||||
specified time range, apply the `WHERE` clause with time-based predicates to the
|
||||
outer query rather than the inner query.
|
||||
For example--the following queries return the same results, but **the query with
|
||||
time-based predicate on the outer query is more performant than the query with
|
||||
time-based predicate on the inner query**:
|
||||
|
||||
{{% influxdb/custom-timestamps %}}
|
||||
|
||||
#### Time bounds on the outer query {note="(Recommended)"}
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
inner_value AS value
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
raw_value as inner_value
|
||||
)
|
||||
WHERE
|
||||
time >= '2022-01-01T08:00:00Z'
|
||||
AND time <= '2022-01-01T20:00:00Z'
|
||||
```
|
||||
|
||||
#### Time bounds on the inner query
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
inner_value AS value
|
||||
FROM
|
||||
(
|
||||
SELECT
|
||||
raw_value as inner_value
|
||||
WHERE
|
||||
time >= '2022-07-19T08:00:00Z'
|
||||
AND time <= '2022-01-01T20:00:00Z'
|
||||
)
|
||||
```
|
||||
{{% /influxdb/custom-timestamps %}}
|
||||
|
||||
### Cannot use multiple SELECT statements in a subquery
|
||||
|
||||
InfluxQL does not support multiple
|
||||
[`SELECT` statements](/influxdb/clustered/reference/influxql/select/)
|
||||
per subquery:
|
||||
|
||||
```sql
|
||||
SELECT_clause FROM (SELECT_statement; SELECT_statement) [...]
|
||||
```
|
||||
|
||||
However, InfluxQL does support multiple nested subqueries per outer query:
|
||||
|
||||
```sql
|
||||
SELECT_clause FROM ( SELECT_clause FROM ( SELECT_statement ) [...] ) [...]
|
||||
------------------ ----------------
|
||||
Subquery 1 Subquery 2
|
||||
```
|
||||
Loading…
Reference in New Issue