# Aggregate Functions

{% columns %}
{% column %}
{% content-ref url="../../server-usage/stored-routines/stored-functions/stored-aggregate-functions" %}
[stored-aggregate-functions](https://mariadb.com/docs/server/server-usage/stored-routines/stored-functions/stored-aggregate-functions)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Stored Aggregate Functions allow users to create custom aggregate functions that process a sequence of rows and return a single summary result. This page provides a general overview.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/avg" %}
[avg](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/avg)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Calculate the average value. This function computes the arithmetic mean of a numeric expression, ignoring `NULL` values.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/bit\_and" %}
[bit\_and](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/bit_and)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Perform a bitwise `AND` operation. This function returns the result of performing a bitwise `AND` on all values in a given expression.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/bit\_or" %}
[bit\_or](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/bit_or)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Perform a bitwise `OR` operation. This function returns the result of performing a bitwise `OR` on all values in a given expression.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/bit\_xor" %}
[bit\_xor](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/bit_xor)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Perform a bitwise `XOR` operation. This function returns the result of performing a bitwise `XOR` on all values in a given expression.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/count-distinct" %}
[count-distinct](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/count-distinct)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Count unique values. This function returns the number of distinct, non-`NULL` values found in the specified column or expression.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/count" %}
[count](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/count)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Complete `COUNT()` function reference: `COUNT(*`) and `COUNT(expr)` syntax, `COUNT(DISTINCT)` usage, `GROUP BY` aggregation, and `OVER(PARTITION BY)` window syntax.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/group\_concat" %}
[group\_concat](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/group_concat)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Complete `GROUP_CONCAT` reference for MariaDB. Complete function guide with syntax, parameters, return values, and usage examples for production use.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/json\_arrayagg" %}
[json\_arrayagg](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/json_arrayagg)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Aggregate values into a JSON array. This function aggregates a result set column into a single JSON array.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/json\_objectagg" %}
[json\_objectagg](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/json_objectagg)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Aggregate key-value pairs into a JSON object. This function aggregates two columns or expressions into a single JSON object.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/max" %}
[max](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/max)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Find the maximum value. This function returns the highest value in a set of values, applicable to numbers, strings, and dates.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/min" %}
[min](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/min)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Find the minimum value. This function returns the lowest value in a set of values, applicable to numbers, strings, and dates.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/std" %}
[std](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/std)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Calculate population standard deviation. This function returns the square root of the population variance. It is a synonym for `STDDEV_POP()`.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/stddev" %}
[stddev](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/stddev)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Calculate population standard deviation. This function is a synonym for `STD()` and `STDDEV_POP()`, returning the square root of the population variance.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/stddev\_pop" %}
[stddev\_pop](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/stddev_pop)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Calculate population standard deviation. This function computes the standard deviation assuming the set of values represents the entire population.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/stddev\_samp" %}
[stddev\_samp](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/stddev_samp)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Calculate sample standard deviation. This function computes the standard deviation assuming the set of values represents a sample of the population.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/sum" %}
[sum](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/sum)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Calculate the total sum. This function returns the sum of all values in a numeric expression, ignoring `NULL` values.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/var\_pop" %}
[var\_pop](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/var_pop)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Calculate population variance. This function computes the statistical variance for a set of values assumed to be the entire population.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/var\_samp" %}
[var\_samp](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/var_samp)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Calculate sample variance. This function computes the statistical variance for a set of values assumed to be a sample of the population.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="aggregate-functions/variance" %}
[variance](https://mariadb.com/docs/server/reference/sql-functions/aggregate-functions/variance)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Calculate population variance. This function is a synonym for VAR\_POP() and returns the variance of a set of values.
{% endcolumn %}
{% endcolumns %}


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