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*SQL aggregate functions are calculated from values in a column, and return a single value.*
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SQL group (aggregate) functions operate on sets of values. If you use an aggregate function in a statement containing no GROUP BY clause, it is equivalent to grouping on all rows.
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General syntax for aggregate functions is: ::
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SELECT "function type" ("column_name")
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The following are examples of aggregate functions:
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* AVG() - Returns the average value
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* COUNT() - Returns the number of rows
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* FIRST() - Returns the first value
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* LAST() - Returns the last value
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* MAX() - Returns the largest value
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* MIN() - Returns the smallest value
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* SUM() - Returns the sum
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The following are examples of aggregate functions:
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**AVG**: Return the average value of the argument. (Does not work with temporal values unless first converted to numeric values.)
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(DISTINCT): Return the count of a number of different values
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:doc:`count`: Return a count of the number of rows returned
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**GROUP_CONCAT**: Return a concatenated string
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**MAX**: Return the maximum value
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**MIN**: Return the minimum value
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**STD**: Return the population standard deviation
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**STDDEV_POP**: Return the population standard deviation
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**STDDEV_SAMP**: Return the sample standard deviation
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**STDDEV**: Return the population standard deviation
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**SUM**: Return the sum. (Does not work with temporal values unless first converted to numeric values.)
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**VAR_POP**: Return the population standard variance
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**VAR_SAMP**: Return the sample variance
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**VARIANCE**: Return the population standard variance
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docs/aggregatefunctions.rst
