Aggregate functions perform a calculation on a set of values and return a single value.

    1. COUNT(col)
    2. COUNT(*)

    Return the number of rows. When col is specified, the count returned will be the number of rows. When * is specified, the count returned will be the total number of rows.

    1. AVG(col)

    Return the average value of a given column.

    1. SUM(col)

    Return the sum value of a given column.

    1. MAX(col)

    Return the max value of a given column.

    1. MIN(col)

    Return the min value of a given column.