docs-v2/content/influxdb/cloud-iox/reference/sql/functions/aggregate.md

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SQL aggregate functions	Aggregate functions	Aggregate data with SQL aggregate functions.	influxdb_cloud_iox name parent Aggregate sql-functions	301	/influxdb/cloud-iox/query-data/sql/aggregate-select/

SQL aggregate functions aggregate values in a specified column for each group or SQL partition and return a single row per group containing the aggregate value.

• General aggregate functions
  • avg
  • count
  • max
  • min
  • sum
• Statistical aggregate functions
  • corr
  • covar
  • covar_pop
  • covar_samp
  • stddev
  • stddev_pop
  • stddev_samp
  • var
  • var_pop
  • var_samp
• Approximate aggregate functions
  • approx_distinct
  • approx_median
  • approx_percentile_cont
  • approx_percentile_cont_with_weight

---

General aggregate functions

• avg
• count
• max
• min
• sum

avg

Returns the average of numeric values in the specified column.

avg(expression)

Arguments:

• expression: Column to operate on.

Aliases:

• mean

{{< expand-wrapper >}} {{% expand "View avg query example" %}}

SELECT 
  location,
  avg(water_level) AS water_level_avg
FROM h2o_feet
GROUP BY location

location	water_level_avg
coyote_creek	5.359142420303919
santa_monica	3.5307120942458843

{{% /expand %}} {{< /expand-wrapper >}}

count

Returns the number of rows in the specified column.

Count includes null values in the total count. To exclude null values from the total count, include <column> IS NOT NULL in the WHERE clause.

count(expression)

Arguments:

• expression: Column to operate on.

{{< expand-wrapper >}} {{% expand "View count query example" %}}

SELECT 
  location,
  count(water_level) AS water_level_count
FROM h2o_feet
GROUP BY location

location	water_level_count
coyote_creek	7604
santa_monica	7654

{{% /expand %}} {{< /expand-wrapper >}}

max

Returns the maximum value in the specified column.

To return both the maximum value and its associated timestamp, use selector_max.

Arguments:

• expression: Column to operate on.

{{< expand-wrapper >}} {{% expand "View max query example" %}}

SELECT 
  location,
  max(water_level) AS water_level_max
FROM h2o_feet
GROUP BY location

location	water_level_max
santa_monica	7.205
coyote_creek	9.964

{{% /expand %}} {{< /expand-wrapper >}}

min

Returns the minimum value in the specified column.

To return both the minimum value and its associated timestamp, use selector_max.

Arguments:

• expression: Column to operate on.

{{< expand-wrapper >}} {{% expand "View min query example" %}}

SELECT 
  location,
  min(water_level) AS water_level_min
FROM h2o_feet
GROUP BY location

location	water_level_min
coyote_creek	-0.61
santa_monica	-0.243

{{% /expand %}} {{< /expand-wrapper >}}

sum

Returns the sum of all values in the specified column.

Arguments:

• expression: Column to operate on.

{{< expand-wrapper >}} {{% expand "View sum query example" %}}

SELECT 
  location,
  sum(water_level) AS water_level_sum
FROM h2o_feet
GROUP BY location

location	water_level_sum
santa_monica	27024.070369358
coyote_creek	40750.918963991004

{{% /expand %}} {{< /expand-wrapper >}}

Statistical aggregate functions

• corr
• covar
• covar_pop
• covar_samp
• stddev
• stddev_pop
• stddev_samp
• var
• var_pop
• var_samp

corr

Returns the coefficient of correlation between two numeric values.

corr(expression1, expression2)

Arguments:

• expression1: First column or literal value to operate on.
• expression2: Second column or literal value to operate on.

{{< expand-wrapper >}} {{% expand "View corr query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  corr(hum, temp) AS correlation
FROM home
GROUP BY room

room	correlation
Living Room	0.43665270457835725
Kitchen	0.6741766954929539

{{% /expand %}} {{< /expand-wrapper >}}

covar

Returns the covariance of a set of number pairs.

covar(expression1, expression2)

Arguments:

• expression1: First column or literal value to operate on.
• expression2: Second column or literal value to operate on.

{{< expand-wrapper >}} {{% expand "View covar query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  covar(hum, temp) AS covar
FROM home
GROUP BY room

Arguments:

• expression1: First column or literal value to operate on.
• expression2: Second column or literal value to operate on.

room	covar
Living Room	0.03346153846153959
Kitchen	0.11134615384615432

{{% /expand %}} {{< /expand-wrapper >}}

covar_pop

Returns the population covariance of a set of number pairs.

covar_pop(expression1, expression2)

Arguments:

• expression1: First column or literal value to operate on.
• expression2: Second column or literal value to operate on.

{{< expand-wrapper >}} {{% expand "View covar_pop query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  covar_pop(hum, temp) AS covar_pop
FROM home
GROUP BY room

room	covar_pop
Kitchen	0.10278106508875783
Living Room	0.030887573964498087

{{% /expand %}} {{< /expand-wrapper >}}

covar_samp

Returns the sample covariance of a set of number pairs.

covar_samp(expression1, expression2)

Arguments:

• expression1: First column or literal value to operate on.
• expression2: Second column or literal value to operate on.

{{< expand-wrapper >}} {{% expand "View covar_samp query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  covar_samp(hum, temp) AS covar_samp
FROM home
GROUP BY room

room	covar_samp
Kitchen	0.11134615384615432
Living Room	0.03346153846153959

{{% /expand %}} {{< /expand-wrapper >}}

stddev

Returns the standard deviation of a set of numbers.

stddev(expression)

Arguments:

• expression: Column or literal value to operate on.

{{< expand-wrapper >}} {{% expand "View stddev query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  stddev(co) AS stddev
FROM home
GROUP BY room

room	stddev
Living Room	5.885662718931967
Kitchen	9.321879418735037

{{% /expand %}} {{< /expand-wrapper >}}

stddev_pop

Returns the population standard deviation of a set of numbers.

stddev_pop(expression)

Arguments:

• expression: Column or literal value to operate on.

{{< expand-wrapper >}} {{% expand "View stddev_pop query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  stddev_pop(co) AS stddev_pop
FROM home
GROUP BY room

room	stddev_pop
Kitchen	8.956172047894082
Living Room	5.654761830612032

{{% /expand %}} {{< /expand-wrapper >}}

stddev_samp

Returns the sample standard deviation of a set of numbers.

stddev_samp(expression)

Arguments:

• expression: Column or literal value to operate on.

{{< expand-wrapper >}} {{% expand "View stddev_samp query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  stddev_samp(co) AS stddev_samp
FROM home
GROUP BY room

room	stddev_samp
Living Room	5.885662718931967
Kitchen	9.321879418735037

{{% /expand %}} {{< /expand-wrapper >}}

---

var

Returns the statistical variance of a set of numbers.

var(expression)

Arguments:

• expression: Column or literal value to operate on.

{{< expand-wrapper >}} {{% expand "View var query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  var(co) AS var
FROM home
GROUP BY room

room	var
Living Room	34.64102564102564
Kitchen	86.89743589743587

{{% /expand %}} {{< /expand-wrapper >}}

var_pop

Returns the statistical population variance of a set of numbers.

var_pop(expression)

Arguments:

• expression: Column or literal value to operate on.

{{< expand-wrapper >}} {{% expand "View var_pop query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  var_pop(co) AS var_pop
FROM home
GROUP BY room

room	var_pop
Living Room	31.976331360946745
Kitchen	80.21301775147927

{{% /expand %}} {{< /expand-wrapper >}}

var_samp

Returns the statistical sample variance of a set of numbers.

var_samp(expression)

Arguments:

• expression: Column or literal value to operate on.

{{< expand-wrapper >}} {{% expand "View var_samp query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  var_samp(co) AS var_samp
FROM home
GROUP BY room

room	var_samp
Kitchen	86.89743589743587
Living Room	34.64102564102564

{{% /expand %}} {{< /expand-wrapper >}}

Approximate aggregate functions

• approx_distinct
• approx_median
• approx_percentile_cont
• approx_percentile_cont_with_weight

approx_distinct

Returns the approximate number of distinct input values calculated using the HyperLogLog algorithm.

approx_distinct(expression)

Arguments

• expression: Column or literal value to operate on.

{{< expand-wrapper >}} {{% expand "View approx_distinct query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  approx_distinct(co::string) AS approx_distinct
FROM home
GROUP BY room

room	approx_distinct
Living Room	7
Kitchen	8

{{% /expand %}} {{< /expand-wrapper >}}

approx_median

Returns the approximate median (50th percentile) of input values. It is an alias of approx_percentile_cont(x, 0.5).

approx_median(expression)

Arguments

• expression: Column or literal value to operate on.

{{< expand-wrapper >}} {{% expand "View approx_median query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  approx_median(temp) AS approx_median
FROM home
GROUP BY room

room	approx_median
Kitchen	22.7
Living Room	22.3

{{% /expand %}} {{< /expand-wrapper >}}

approx_percentile_cont

Returns the approximate percentile of input values using the t-digest algorithm.

approx_percentile_cont(expression, percentile, centroids)

Arguments

• expression: Column or literal value to operate on.

• percentile: Percentile to compute. Must be a float value between 0 and 1 (inclusive).

• centroids: Number of centroids to use in the t-digest algorithm. Default is 100.

  If there are this number or fewer unique values, you can expect an exact result. A higher number of centroids results in a more accurate approximation, but requires more memory to compute.

{{< expand-wrapper >}} {{% expand "View approx_percentile_cont query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  approx_percentile_cont(temp, 0.99) AS "99th_percentile"
FROM home
GROUP BY room

room	99th_percentile
Kitchen	23.3
Living Room	22.8

{{% /expand %}} {{< /expand-wrapper >}}

approx_percentile_cont_with_weight

Returns the weighted approximate percentile of input values using the t-digest algorithm.

approx_percentile_cont_with_weight(expression, weight, percentile)

Arguments

• expression: Column or literal value to operate on.
• weight: Column or literal value to use as weight.
• percentile: Percentile to compute. Must be a float value between 0 and 1 (inclusive).

{{< expand-wrapper >}} {{% expand "View approx_percentile_cont_with_weight query example" %}}

The following example uses the sample data set provided in Get started with InfluxDB tutorial.

SELECT
  room,
  approx_percentile_cont_with_weight(temp, co, 0.99) AS "co_weighted_99th_percentile"
FROM home
GROUP BY room

room	co_weighted_99th_percentile
Kitchen	23.3
Living Room	22.8

{{% /expand %}} {{< /expand-wrapper >}}