--- title: InfluxQL aggregate functions description: Aggregate data with InfluxQL aggregate functions. url: https://docs.influxdata.com/influxdb/v2/query-data/influxql/functions/aggregates/ estimated_tokens: 23122 product: InfluxDB OSS v2 version: v2 --- # InfluxQL aggregate functions This page documents an earlier version of InfluxDB OSS. [InfluxDB 3 Core](/influxdb3/core/) is the latest stable version. #### API token hashing is enabled by default in InfluxDB OSS 2.9.0 Stronger token security: tokens are stored as hashes on disk, so a copy of the database file doesn’t expose usable tokens. Existing tokens are hashed on first startup and the original strings can’t be recovered afterward — **capture any plaintext tokens you still need before you upgrade**. For more information, see [Token hashing](/influxdb/v2/admin/tokens/#token-hashing). Use aggregate functions to assess, aggregate, and return values in your data. Aggregate functions return one row containing the aggregate values from each InfluxQL group. Each aggregate function below covers **syntax** including parameters to pass to the function, and **examples** of how to use the function. Examples use [NOAA water sample data](/influxdb/v2/reference/sample-data/#noaa-water-sample-data). - [COUNT()](#count) - [DISTINCT()](#distinct) - [INTEGRAL()](#integral) - [MEAN()](#mean) - [MEDIAN()](#median) - [MODE()](#mode) - [SPREAD()](#spread) - [STDDEV()](#stddev) - [SUM()](#sum) ## COUNT() Returns the number of non-null [field values](/influxdb/v2/reference/glossary/#field-value). Supports all field value [data types](/influxdb/v2/reference/glossary/#data-type). ### Syntax ```sql SELECT COUNT( [ * | | // ] ) FROM_clause [WHERE_clause] [GROUP_BY_clause] [ORDER_BY_clause] [LIMIT_clause] [OFFSET_clause] [SLIMIT_clause] [SOFFSET_clause] ``` `COUNT(*)` Returns the number of field values associated with each field key in the [measurement](/influxdb/v2/reference/glossary/#measurement). `COUNT(field_key)` Returns the number of field values associated with the [field key](/influxdb/v2/reference/glossary/#field-key). `COUNT(/regular_expression/)` Returns the number of field values associated with each field key that matches the [regular expression](/influxdb/v2/query-data/influxql/explore-data/#regular-expressions). #### Examples [](#count-values-for-a-field) Count values for a field Return the number of non-null field values in the `water_level` field key in the `h2o_feet` measurement. ```sql SELECT COUNT("water_level") FROM "h2o_feet" ``` name: h2o\_feet | time | count | | --- | --- | | 1970-01-01T00:00:00Z | 61026.0000000000 | [](#count-values-for-each-field-in-a-measurement) Count values for each field in a measurement Return the number of non-null field values for each field key associated with the `h2o_feet` measurement. The `h2o_feet` measurement has two field keys: `level description` and `water_level`. ```sql SELECT COUNT(*) FROM "h2o_feet" ``` name: h2o\_feet | time | count_level description | count_water_level | | --- | --- | --- | | 1970-01-01T00:00:00Z | 61026.0000000000 | 61026.0000000000 | [](#count-the-values-that-match-a-regular-expression) Count the values that match a regular expression Return the number of non-null field values for every field key that contains the word `water` in the `h2o_feet` measurement. ```sql SELECT COUNT(/water/) FROM "h2o_feet" ``` name: h2o\_feet | time | count_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 61026.0000000000 | [](#count-distinct-values-for-a-field) Count distinct values for a field Return the number of unique field values for the `level description` field key and the `h2o_feet` measurement. InfluxQL supports nesting [DISTINCT()](#distinct) in `COUNT()`. ```sql SELECT COUNT(DISTINCT("level description")) FROM "h2o_feet" ``` name: h2o\_feet | time | count | | --- | --- | | 1970-01-01T00:00:00Z | 4.0000000000 | ## DISTINCT() Returns the list of unique [field values](/influxdb/v2/reference/glossary/#field-value). Supports all field value [data types](/influxdb/v2/reference/glossary/#data-type). InfluxQL supports nesting `DISTINCT()` with [`COUNT()`](#count). ### Syntax ```sql SELECT DISTINCT( [ | // ] ) FROM_clause [WHERE_clause] [GROUP_BY_clause] [ORDER_BY_clause] [LIMIT_clause] [OFFSET_clause] [SLIMIT_clause] [SOFFSET_clause] ``` `DISTINCT(field_key)` Returns the unique field values associated with the [field key](/influxdb/v2/reference/glossary/#field-key). #### Examples [](#list-the-distinct-field-values-associated-with-a-field-key) List the distinct field values associated with a field key Return a tabular list of the unique field values in the `level description` field key in the `h2o_feet` measurement. ```sql SELECT DISTINCT("level description") FROM "h2o_feet" ``` name: h2o\_feet | time | distinct | | --- | --- | | 1970-01-01T00:00:00Z | between 6 and 9 feet | | 1970-01-01T00:00:00Z | below 3 feet | | 1970-01-01T00:00:00Z | between 3 and 6 feet | | 1970-01-01T00:00:00Z | at or greater than 9 feet | ## INTEGRAL() Returns the area under the curve for subsequent [field values](/influxdb/v2/reference/glossary/#field-value). `INTEGRAL()` does not support [`fill()`](/influxdb/v2/query-data/influxql/explore-data/group-by/#group-by-time-intervals-and-fill). `INTEGRAL()` supports int64 and float64 field value [data types](/influxdb/v2/reference/glossary/#data-type). ### Syntax ```sql SELECT INTEGRAL( [ * | | // ] [ , ] ) FROM_clause [WHERE_clause] [GROUP_BY_clause] [ORDER_BY_clause] [LIMIT_clause] [OFFSET_clause] [SLIMIT_clause] [SOFFSET_clause] ``` InfluxDB calculates the area under the curve for subsequent field values and converts those results into the summed area per `unit`. The `unit` argument is an integer followed by an optional [duration literal](/influxdb/v2/reference/syntax/influxql/spec/#literals). If the query does not specify the `unit`, the unit defaults to one second (`1s`). `INTEGRAL(field_key)` Returns the area under the curve for subsequent field values associated with the [field key](/influxdb/v2/reference/glossary/#field-key). `INTEGRAL(/regular_expression/)` Returns the area under the curve for subsequent field values associated with each field key that matches the [regular expression](/influxdb/v2/query-data/influxql/explore-data/#regular-expressions). `INTEGRAL(*)` Returns the average field value associated with each field key in the [measurement](/influxdb/v2/reference/glossary/#measurement). #### Examples The following examples use a subset of the [NOAA water sample data](/influxdb/v2/reference/sample-data/#noaa-water-sample-data) data: ```sql SELECT "water_level" FROM "h2o_feet" WHERE "location" = 'santa_monica' AND time >= '2019-08-18T00:00:00Z' AND time <= '2019-08-18T00:30:00Z' ``` name: h2o\_feet | time | water_level | | --- | --- | | 2019-08-18T00:00:00Z | 2.3520000000 | | 2019-08-18T00:06:00Z | 2.3790000000 | | 2019-08-18T00:12:00Z | 2.3430000000 | | 2019-08-18T00:18:00Z | 2.3290000000 | | 2019-08-18T00:24:00Z | 2.2640000000 | | 2019-08-18T00:30:00Z | 2.2670000000 | [](#calculate-the-integral-for-the-field-values-associated-with-a-field-key) Calculate the integral for the field values associated with a field key Return the area under the curve (in seconds) for the field values associated with the `water_level` field key and in the `h2o_feet` measurement. ```sql SELECT INTEGRAL("water_level") FROM "h2o_feet" WHERE "location" = 'santa_monica' AND time >= '2019-08-18T00:00:00Z' AND time <= '2019-08-18T00:30:00Z' ``` name: h2o\_feet | time | integral | | --- | --- | | 1970-01-01T00:00:00Z | 4184.8200000000 | [](#calculate-the-integral-for-the-field-values-associated-with-a-field-key-and-specify-the-unit-option) Calculate the integral for the field values associated with a field key and specify the unit option Return the area under the curve (in minutes) for the field values associated with the `water_level` field key and in the `h2o_feet` measurement. ```sql SELECT INTEGRAL("water_level",1m) FROM "h2o_feet" WHERE "location" = 'santa_monica' AND time >= '2019-08-18T00:00:00Z' AND time <= '2019-08-18T00:30:00Z' ``` name: h2o\_feet | time | integral | | --- | --- | | 1970-01-01T00:00:00Z | 69.7470000000 | [](#calculate-the-integral-for-the-field-values-associated-with-each-field-key-in-a-measurement-and-specify-the-unit-option) Calculate the integral for the field values associated with each field key in a measurement and specify the unit option Return the area under the curve (in minutes) for the field values associated with each field key that stores numeric values in the `h2o_feet` measurement. The `h2o_feet` measurement has on numeric field: `water_level`. ```sql SELECT INTEGRAL(*,1m) FROM "h2o_feet" WHERE "location" = 'santa_monica' AND time >= '2019-08-18T00:00:00Z' AND time <= '2019-08-18T00:30:00Z' ``` name: h2o\_feet | time | integral_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 69.7470000000 | [](#calculate-the-integral-for-the-field-values-associated-with-each-field-key-that-matches-a-regular-expression-and-specify-the-unit-option) Calculate the integral for the field values associated with each field key that matches a regular expression and specify the unit option Return the area under the curve (in minutes) for the field values associated with each field key that stores numeric values includes the word `water` in the `h2o_feet` measurement. ```sql SELECT INTEGRAL(/water/,1m) FROM "h2o_feet" WHERE "location" = 'santa_monica' AND time >= '2019-08-18T00:00:00Z' AND time <= '2019-08-18T00:30:00Z' ``` name: h2o\_feet | time | integral_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 69.7470000000 | [](#calculate-the-integral-for-the-field-values-associated-with-a-field-key-and-include-several-clauses) Calculate the integral for the field values associated with a field key and include several clauses Return the area under the curve (in minutes) for the field values associated with the `water_level` field key and in the `h2o_feet` measurement in the [time range](/influxdb/v2/query-data/influxql/explore-data/time-and-timezone/#time-syntax) between `2019-08-18T00:00:00Z` and `2019-08-18T00:30:00Z`, [grouped](/influxdb/v2/query-data/influxql/explore-data/group-by/#group-by-time-intervals) results into 12-minute intervals, and [limit](/influxdb/v2/query-data/influxql/explore-data/limit-and-slimit/) the number of results returned to one. ```sql SELECT INTEGRAL("water_level",1m) FROM "h2o_feet" WHERE "location" = 'santa_monica' AND time >= '2019-08-18T00:00:00Z' AND time <= '2019-08-18T00:30:00Z' GROUP BY time(12m) LIMIT 1 ``` name: h2o\_feet | time | integral | | --- | --- | | 2019-08-18T00:00:00Z | 28.3590000000 | ## MEAN() Returns the arithmetic mean (average) of [field values](/influxdb/v2/reference/glossary/#field-value). `MEAN()` supports int64 and float64 field value [data types](/influxdb/v2/reference/glossary/#data-type). ### Syntax ```sql SELECT MEAN( [ * | | // ] ) FROM_clause [WHERE_clause] [GROUP_BY_clause] [ORDER_BY_clause] [LIMIT_clause] [OFFSET_clause] [SLIMIT_clause] [SOFFSET_clause] ``` `MEAN(field_key)` Returns the average field value associated with the [field key](/influxdb/v2/reference/glossary/#field-key). \`MEAN(/regular\_expression/) Returns the average field value associated with each field key that matches the [regular expression](/influxdb/v2/query-data/influxql/explore-data/#regular-expressions). `MEAN(*)` Returns the average field value associated with each field key in the [measurement](/influxdb/v2/reference/glossary/#measurement). #### Examples [](#calculate-the-mean-field-value-associated-with-a-field-key) Calculate the mean field value associated with a field key Return the average field value in the `water_level` field key in the `h2o_feet` measurement. ```sql SELECT MEAN("water_level") FROM "h2o_feet" ``` name: h2o\_feet | time | mean | | --- | --- | | 1970-01-01T00:00:00Z | 4.4418674882 | [](#calculate-the-mean-field-value-associated-with-each-field-key-in-a-measurement) Calculate the mean field value associated with each field key in a measurement Return the average field value for every field key that stores numeric values in the `h2o_feet` measurement. The `h2o_feet` measurement has one numeric field: `water_level`. ```sql SELECT MEAN(*) FROM "h2o_feet" ``` name: h2o\_feet | time | mean_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 4.4418674882 | [](#calculate-the-mean-field-value-associated-with-each-field-key-that-matches-a-regular-expression) Calculate the mean field value associated with each field key that matches a regular expression Return the average field value for each field key that stores numeric values and includes the word `water` in the `h2o_feet` measurement. ```sql SELECT MEAN(/water/) FROM "h2o_feet" ``` name: h2o\_feet | time | mean_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 4.4418674882 | [](#calculate-the-mean-field-value-associated-with-a-field-key-and-include-several-clauses) Calculate the mean field value associated with a field key and include several clauses Return the average of the values in the `water_level` field key in the [time range](/influxdb/v2/query-data/influxql/explore-data/time-and-timezone/#time-syntax) between `2019-08-18T00:00:00Z` and `2019-08-18T00:30:00Z` and [group](/influxdb/v2/query-data/influxql/explore-data/group-by/) results into 12-minute time intervals and per tag. Then [fill](/influxdb/v2/query-data/influxql/explore-data/group-by/#group-by-time-intervals-and-fill) empty time intervals with `9.01` and [limit](/influxdb/influxdb/v2/query-data/influxql/explore-data/limit-and-slimit/) the number of points and series returned to seven and one. ```sql SELECT MEAN("water_level") FROM "h2o_feet" WHERE time >= '2019-08-18T00:00:00Z' AND time <= '2019-08-18T00:30:00Z' GROUP BY time(12m),* fill(9.01) LIMIT 7 SLIMIT 1 ``` name: h2o\_feet tags: location=coyote\_creek | time | mean | | --- | --- | | 2019-08-18T00:00:00Z | 8.4615000000 | | 2019-08-18T00:12:00Z | 8.2725000000 | | 2019-08-18T00:24:00Z | 8.0710000000 | ## MEDIAN() Returns the middle value from a sorted list of [field values](/influxdb/v2/reference/glossary/#field-value). `MEDIAN()` supports int64 and float64 field value [data types](/influxdb/v2/reference/glossary/#data-type). **Note:** `MEDIAN()` is nearly equivalent to [`PERCENTILE(field_key, 50)`](/influxdb/v2/query-data/influxql/functions/selectors/#percentile), except `MEDIAN()` returns the average of the two middle field values if the field contains an even number of values. ### Syntax ```sql SELECT MEDIAN( [ * | | // ] ) FROM_clause [WHERE_clause] [GROUP_BY_clause] [ORDER_BY_clause] [LIMIT_clause] [OFFSET_clause] [SLIMIT_clause] [SOFFSET_clause] ``` `MEDIAN(field_key)` Returns the middle field value associated with the [field key](/influxdb/v2/reference/glossary/#field-key). `MEDIAN(/regular_expression/)` Returns the middle field value associated with each field key that matches the [regular expression](/influxdb/v2/query-data/influxql/explore-data/#regular-expressions). `MEDIAN(*)` Returns the middle field value associated with each field key in the [measurement](/influxdb/v2/reference/glossary/#measurement). #### Examples [](#calculate-the-median-field-value-associated-with-a-field-key) Calculate the median field value associated with a field key Return the middle field value in the `water_level` field key and in the `h2o_feet` measurement. ```sql SELECT MEDIAN("water_level") FROM "h2o_feet" ``` name: h2o\_feet | time | median | | --- | --- | | 1970-01-01T00:00:00Z | 4.1240000000 | [](#calculate-the-median-field-value-associated-with-each-field-key-in-a-measurement) Calculate the median field value associated with each field key in a measurement Return the middle field value for every field key that stores numeric values in the `h2o_feet` measurement. The `h2o_feet` measurement has one numeric field: `water_level`. ```sql SELECT MEDIAN(*) FROM "h2o_feet" ``` name: h2o\_feet | time | median_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 4.1240000000 | [](#calculate-the-median-field-value-associated-with-each-field-key-that-matches-a-regular-expression) Calculate the median field value associated with each field key that matches a regular expression Return the middle field value for every field key that stores numeric values and includes the word `water` in the `h2o_feet` measurement. ```sql SELECT MEDIAN(/water/) FROM "h2o_feet" ``` name: h2o\_feet | time | median_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 4.1240000000 | [](#calculate-the-median-field-value-associated-with-a-field-key-and-include-several-clauses) Calculate the median field value associated with a field key and include several clauses Return the middle field value in the `water_level` field key in the [time range](/influxdb/v2/query-data/influxql/explore-data/time-and-timezone/#time-syntax) between `2019-08-18T00:00:00Z` and `2019-08-18T00:30:00Z` and [group](/influxdb/v2/query-data/influxql/explore-data/group-by/) results into 12-minute time intervals and per tag. Then [fill](/influxdb/v2/query-data/influxql/explore-data/group-by/#group-by-time-intervals-and-fill) empty time intervals with `700` , [limit](/influxdb/influxdb/v2/query-data/influxql/explore-data/limit-and-slimit/) the number of points and series returned to seven and one, and [offset](/influxdb/v2/query-data/influxql/explore-data/limit-and-slimit/) the series returned by one. ```sql SELECT MEDIAN("water_level") FROM "h2o_feet" WHERE time >= '2019-08-18T00:00:00Z' AND time <= '2019-08-18T00:30:00Z' GROUP BY time(12m),* fill(700) LIMIT 7 SLIMIT 1 SOFFSET 1 ``` name: h2o\_feet tags: location=santa\_monica | time | median | | --- | --- | | 2019-08-18T00:00:00Z | 2.3655000000 | | 2019-08-18T00:12:00Z | 2.3360000000 | | 2019-08-18T00:24:00Z | 2.2655000000 | ## MODE() Returns the most frequent value in a list of [field values](/influxdb/v2/reference/glossary/#field-value). `MODE()` supports all field value [data types](/influxdb/v2/reference/glossary/#data-type). **Note:** `MODE()` returns the field value with the earliest [timestamp](/influxdb/v2/reference/glossary/#timestamp) if there’s a tie between two or more values for the maximum number of occurrences. ### Syntax ```sql SELECT MODE( [ * | | // ] ) FROM_clause [WHERE_clause] [GROUP_BY_clause] [ORDER_BY_clause] [LIMIT_clause] [OFFSET_clause] [SLIMIT_clause] [SOFFSET_clause] ``` `MODE(field_key)` Returns the most frequent field value associated with the [field key](/influxdb/v2/reference/glossary/#field-key). `MODE(/regular_expression/)` Returns the most frequent field value associated with each field key that matches the [regular expression](/influxdb/v2/query-data/influxql/explore-data/#regular-expressions). `MODE(*)` Returns the most frequent field value associated with each field key in the [measurement](/influxdb/v2/reference/glossary/#measurement). #### Examples [](#calculate-the-mode-field-value-associated-with-a-field-key) Calculate the mode field value associated with a field key Return the most frequent field value in the `level description` field key and in the `h2o_feet` measurement. ```sql SELECT MODE("level description") FROM "h2o_feet" ``` name: h2o\_feet | time | mode | | --- | --- | | 1970-01-01T00:00:00Z | between 3 and 6 feet | [](#calculate-the-mode-field-value-associated-with-each-field-key-in-a-measurement) Calculate the mode field value associated with each field key in a measurement Return the most frequent field value for every field key in the `h2o_feet` measurement. The `h2o_feet` measurement has two field keys: `level description` and `water_level`. ```sql SELECT MODE(*) FROM "h2o_feet" ``` name: h2o\_feet | time | mode_level description | mode_water_level | | --- | --- | --- | | 1970-01-01T00:00:00Z | between 3 and 6 feet | 2.6900000000 | [](#calculate-the-mode-field-value-associated-with-each-field-key-that-matches-a-regular-expression) Calculate the mode field value associated with each field key that matches a regular expression Return the most frequent field value for every field key that includes the word `/water/` in the `h2o_feet` measurement. ```sql SELECT MODE(/water/) FROM "h2o_feet" ``` name: h2o\_feet | time | mode_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 2.6900000000 | [](#calculate-the-mode-field-value-associated-with-a-field-key-and-include-several-clauses) Calculate the mode field value associated with a field key and include several clauses Return the mode of the values associated with the `water_level` field key in the [time range](/influxdb/v2/query-data/influxql/explore-data/time-and-timezone/#time-syntax) between `2019-08-18T00:00:00Z` and `2019-08-18T00:30:00Z` and [group](/influxdb/v2/query-data/influxql/explore-data/group-by/) results into 12-minute time intervals and per tag. Then [limits](/influxdb/influxdb/v2/query-data/influxql/explore-data/limit-and-slimit/) the number of points and series returned to three and one, and it \[offsets\](/influxdb/v2/query-data/influxql/explore-data #the-offset-and-soffset-clauses) the series returned by one. ```sql SELECT MODE("level description") FROM "h2o_feet" WHERE time >= '2019-08-18T00:00:00Z' AND time <= '2019-08-18T00:30:00Z' GROUP BY time(12m),* LIMIT 3 SLIMIT 1 SOFFSET 1 ``` name: h2o\_feet tags: location=santa\_monica | time | mode | | --- | --- | | 2019-08-18T00:00:00Z | below 3 feet | | 2019-08-18T00:12:00Z | below 3 feet | | 2019-08-18T00:24:00Z | below 3 feet | ## SPREAD() Returns the difference between the minimum and maximum [field values](/influxdb/v2/reference/glossary/#field-value). `SPREAD()` supports int64 and float64 field value [data types](/influxdb/v2/reference/glossary/#data-type). ### Syntax ```sql SELECT SPREAD( [ * | | // ] ) FROM_clause [WHERE_clause] [GROUP_BY_clause] [ORDER_BY_clause] [LIMIT_clause] [OFFSET_clause] [SLIMIT_clause] [SOFFSET_clause] ``` `SPREAD(field_key)` Returns the difference between the minimum and maximum field values associated with the [field key](/influxdb/v2/reference/glossary/#field-key). `SPREAD(/regular_expression/)` Returns the difference between the minimum and maximum field values associated with each field key that matches the [regular expression](/influxdb/v2/query-data/influxql/explore-data/#regular-expressions). `SPREAD(*)` Returns the difference between the minimum and maximum field values associated with each field key in the [measurement](/influxdb/v2/reference/glossary/#measurement). #### Examples [](#calculate-the-spread-for-the-field-values-associated-with-a-field-key) Calculate the spread for the field values associated with a field key Return the difference between the minimum and maximum field values in the `water_level` field key and in the `h2o_feet` measurement. ```sql SELECT SPREAD("water_level") FROM "h2o_feet" ``` name: h2o\_feet | time | spread | | --- | --- | | 1970-01-01T00:00:00Z | 10.5740000000 | [](#calculate-the-spread-for-the-field-values-associated-with-each-field-key-in-a-measurement) Calculate the spread for the field values associated with each field key in a measurement Return the difference between the minimum and maximum field values for every field key that stores numeric values in the `h2o_feet` measurement. The `h2o_feet` measurement has one numeric field: `water_level`. ```sql SELECT SPREAD(*) FROM "h2o_feet" ``` name: h2o\_feet | time | spread_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 10.5740000000 | [](#calculate-the-spread-for-the-field-values-associated-with-each-field-key-that-matches-a-regular-expression) Calculate the spread for the field values associated with each field key that matches a regular expression Return the difference between the minimum and maximum field values for every field key that stores numeric values and includes the word `water` in the `h2o_feet` measurement. ```sql SELECT SPREAD(/water/) FROM "h2o_feet" ``` name: h2o\_feet | time | spread_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 10.5740000000 | [](#calculate-the-spread-for-the-field-values-associated-with-a-field-key-and-include-several-clauses) Calculate the spread for the field values associated with a field key and include several clauses Return the difference between the minimum and maximum field values in the `water_level` field key in the [time range](/influxdb/v2/query-data/influxql/explore-data/time-and-timezone/#time-syntax) between `2019-08-18T00:00:00Z` and `2019-08-18T00:30:00Z` and [group](/influxdb/v2/query-data/influxql/explore-data/group-by/) results into 12-minute time intervals and per tag. Then [fill](/influxdb/v2/query-data/influxql/explore-data/group-by/#group-by-time-intervals-and-fill) empty time intervals with `18`, [lim ts](/influxdb/v2/query-data/influxql/explore-data/limit-and-slimit/) the number of points and series returned to three and one, and [offsets](/influxdb/v2/query-data/influxql/explore-data/limit-and-slimit/) the series returned by one. ```sql SELECT SPREAD("water_level") FROM "h2o_feet" WHERE time >= '2019-08-18T00:00:00Z' AND time <= '2019-08-18T00:30:00Z' GROUP BY time(12m),* fill(18) LIMIT 3 SLIMIT 1 SOFFSET 1 ``` name: h2o\_feet tags: location=santa\_monica | time | spread | | --- | --- | | 2019-08-18T00:00:00Z | 0.0270000000 | | 2019-08-18T00:12:00Z | 0.0140000000 | | 2019-08-18T00:24:00Z | 0.0030000000 | ## STDDEV() Returns the standard deviation of [field values](/influxdb/v2/reference/glossary/#field-value). `STDDEV()` supports int64 and float64 field value [data types](/influxdb/v2/reference/glossary/#data-type). ### Syntax ```sql SELECT STDDEV( [ * | | // ] ) FROM_clause [WHERE_clause] [GROUP_BY_clause] [ORDER_BY_clause] [LIMIT_clause] [OFFSET_clause] [SLIMIT_clause] [SOFFSET_clause] ``` `STDDEV(field_key)` Returns the standard deviation of field values associated with the [field key](/influxdb/v2/reference/glossary/#field-key). `STDDEV(/regular_expression/)` Returns the standard deviation of field values associated with each field key that matches the [regular expression](/influxdb/v2/query-data/influxql/explore-data/#regular-expressions). `STDDEV(*)` Returns the standard deviation of field values associated with each field key in the [measurement](/influxdb/v2/reference/glossary/#measurement). #### Examples [](#calculate-the-standard-deviation-for-the-field-values-associated-with-a-field-key) Calculate the standard deviation for the field values associated with a field key Return the standard deviation of the field values in the `water_level` field key and in the `h2o_feet` measurement. ```sql SELECT STDDEV("water_level") FROM "h2o_feet" ``` name: h2o\_feet | time | stddev | | --- | --- | | 1970-01-01T00:00:00Z | 2.2789744110 | [](#calculate-the-standard-deviation-for-the-field-values-associated-with-each-field-key-in-a-measurement) Calculate the standard deviation for the field values associated with each field key in a measurement Return the standard deviation of numeric fields in the `h2o_feet` measurement. The `h2o_feet` measurement has one numeric field: `water_level`. ```sql SELECT STDDEV(*) FROM "h2o_feet" ``` name: h2o\_feet | time | stddev_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 2.2789744110 | [](#calculate-the-standard-deviation-for-the-field-values-associated-with-each-field-key-that-matches-a-regular-expression) Calculate the standard deviation for the field values associated with each field key that matches a regular expression Return the standard deviation of numeric fields with `water` in the field key in the `h2o_feet` measurement. ```sql SELECT STDDEV(/water/) FROM "h2o_feet" ``` name: h2o\_feet | time | stddev_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 2.2789744110 | [](#calculate-the-standard-deviation-for-the-field-values-associated-with-a-field-key-and-include-several-clauses) Calculate the standard deviation for the field values associated with a field key and include several clauses Return the standard deviation of the field values in the `water_level` field key in the [time range](/influxdb/v2/query-data/influxql/explore-data/time-and-timezone/#time-syntax) between `2019-08-18T00:00:00Z` and `2019-08-18T00:30:00Z` and [group](/influxdb/v2/query-data/influxql/explore-data/group-by/) results into 12-minute time intervals and per tag. Then [fill](/influxdb/v2/query-data/influxql/explore-data/group-by/#group-by-time-intervals-and-fill) empty time intervals with `18000`, [limit](/influxdb/influxdb/v2/query-data/influxql/explore-data/limit-and-slimit/) the number of points and series returned to two and one, and [offsets](/influxdb/v2/query-data/influxql/explore-data/limit-and-slimit/) the series returned by one. ```sql SELECT STDDEV("water_level") FROM "h2o_feet" WHERE time >= '2019-08-18T00:00:00Z' AND time <= '2019-08-18T00:30:00Z' GROUP BY time(12m),* fill(18000) LIMIT 2 SLIMIT 1 SOFFSET 1 ``` name: h2o\_feet tags: location=santa\_monica | time | stddev | | --- | --- | | 2019-08-18T00:00:00Z | 0.0190918831 | | 2019-08-18T00:12:00Z | 0.0098994949 | ## SUM() Returns the sum of [field values](/influxdb/v2/reference/glossary/#field-value). `SUM()` supports int64 and float64 field value [data types](/influxdb/v2/reference/glossary/#data-type). ### Syntax ```sql SELECT SUM( [ * | | // ] ) FROM_clause [WHERE_clause] [GROUP_BY_clause] [ORDER_BY_clause] [LIMIT_clause] [OFFSET_clause] [SLIMIT_clause] [SOFFSET_clause] ``` `SUM(field_key)` Returns the sum of field values associated with the [field key](/influxdb/v2/reference/glossary/#field-key). `SUM(/regular_expression/)` Returns the sum of field values associated with each field key that matches the [regular expression](/influxdb/v2/query-data/influxql/explore-data/#regular-expressions). `SUM(*)` Returns the sums of field values associated with each field key in the [measurement](/influxdb/v2/reference/glossary/#measurement). #### Examples [](#calculate-the-sum-of-the-field-values-associated-with-a-field-key) Calculate the sum of the field values associated with a field key Return the summed total of the field values in the `water_level` field key and in the `h2o_feet` measurement. ```sql SELECT SUM("water_level") FROM "h2o_feet" ``` name: h2o\_feet | time | sum | | --- | --- | | 1970-01-01T00:00:00Z | 271069.4053333958 | [](#calculate-the-sum-of-the-field-values-associated-with-each-field-key-in-a-measurement) Calculate the sum of the field values associated with each field key in a measurement Return the summed total of numeric fields in the `h2o_feet` measurement. The `h2o_feet` measurement has one numeric field: `water_level`. ```sql SELECT SUM(*) FROM "h2o_feet" ``` name: h2o\_feet | time | sum_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 271069.4053333958 | [](#calculate-the-sum-of-the-field-values-associated-with-each-field-key-that-matches-a-regular-expression) Calculate the sum of the field values associated with each field key that matches a regular expression Return the summed total of numeric fields with `water` in the field key in the `h2o_feet` measurement. ```sql SELECT SUM(/water/) FROM "h2o_feet" ``` name: h2o\_feet | time | sum_water_level | | --- | --- | | 1970-01-01T00:00:00Z | 271069.4053333958 | [](#calculate-the-sum-of-the-field-values-associated-with-a-field-key-and-include-several-clauses) Calculate the sum of the field values associated with a field key and include several clauses Return the summed total of the field values in the `water_level` field key in the [time range](/influxdb/v2/query-data/influxql/explore-data/time-and-timezone/#time-syntax) between `2019-08-18T00:00:00Z` and `2019-08-18T00:30:00Z` and [group](/influxdb/v2/query-data/influxql/explore-data/group-by/) results into 12-minute time intervals and per tag. Then [fill](/influxdb/v2/query-data/influxql/explore-data/group-by/#group-by-time-intervals-and-fill) empty time intervals with 18000, and [limit](/influxdb/influxdb/v2/query-data/influxql/explore-data/limit-and-slimit/) the number of points and series returned to four and one. ```sql SELECT SUM("water_level") FROM "h2o_feet" WHERE time >= '2019-08-18T00:00:00Z' AND time <= '2019-08-18T00:30:00Z' GROUP BY time(12m),* fill(18000) LIMIT 4 SLIMIT 1 ``` name: h2o\_feet tags: location=coyote\_creek | time | sum | | --- | --- | | 2019-08-18T00:00:00Z | 16.9230000000 | | 2019-08-18T00:12:00Z | 16.5450000000 | | 2019-08-18T00:24:00Z | 16.1420000000 |