Please explain what are aggregate functions?

Submitted by: Muhammad
Aggregate functions perform calculations on a set of values and return a single value. The common aggregate functions are:

☛ COUNT (counts the number of rows in the table)
☛ SUM (returns the sum of all values of a numeric column)
☛ AVG (returns the average of all values of a numeric column)
☛ MIN (returns the lowest value of a numeric column)
☛ MAX (returns the highest value of a numeric column).

Aggregate functions are frequently used in combination with the GROUP BY statement.
Submitted by: Muhammad

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