SQL COMMANDS Aggregation function

• Aggregate functions combine multiple rows together to form a single value of more meaningful information.
• COUNT takes the name of a column(s) as an argument and counts the number of rows where the value(s) is not NULL.
• GROUP BY is a clause used with aggregate functions to combine data from one or more columns.
• SUM() takes the column name as an argument and returns the sum of all the values in that column.
• MAX() takes the column name as an argument and returns the largest value in that column.
• MIN() takes the column name as an argument and returns the smallest value in that column.
• AVG() takes a column name as an argument and returns the average value for that column.
• ROUND() takes two arguments, a column name and the number of decimal places to round the values in that column.