Summarizing data
Sometimes, we are just looking for information about our data. For this, MariaDB has several built-in functions: AVG, COUNT, MIN, MAX, and SUM.
The AVG function
The AVG function is used for obtaining the average of the data in a column. For example, combined with the TIMESTAMPDIFF and CURDATE functions, we can use the AVG function to calculate the average age of all of the people in the employees table.
The CURDATE function doesn't take any arguments and when called, it simply returns the current date.
The TIMESTAMPDIFF function takes three arguments—the unit to count by and two dates, and then outputs the difference between the two. The unit is one of several time units, including MINUTE, HOUR, DAY, WEEK, MONTH, QUARTER, and YEAR.
Tip
The TIMESTAMPDIFF and CURDATE functions are just two of several functions that make working with dates and times easier. Find out more about them at the following location:
Putting all three functions...
