Chapter 7, Problem 33P

Program Plan Intro

Aggregate Functions:

SQL has some built-in functions and they are called as aggregate functions. SQL contains five built-in functions. They are:

• SUM – This function is used to add values from the particular column.
  • Syntax: SELECT SUM(column_Name) FROM table_Name;
• COUNT – This is used to count the number of rows for the particular column.
  • Syntax: SELECT COUNT(column_Name) FROM table_Name;
• MAX – This function is used to get the maximum value from the column.
  • Syntax: SELECT MAX(column_Name) FROM table_Name;
• MIN – This function is used to get the minimum value from the column.
  • Syntax: SELECT MIN(column_Name) FROM table_Name;
• AVG – This function is used to get the average of all the values from the column.

GROUP BY Clause:

The GROUPBY clause is used to group the result of a SELECT statement done on a table where the tuple values are similar for more than one column

Syntax:

SELECT expression1, expression2, expression_n, aggregate_function(expression)FROM table_name WHERE conditions GROUP BY expression1, expression2, expression_n;