GROUP BY

In Oracle GROUP BY clause is used with SELECT statement to collect data from multiple records and group the results by one or more columns.

Syntax:

SELECT col1, col2, ... col_n,  
aggregate_function (col1)  
FROM tables  
WHERE conditions  
GROUP BY col1, col2, ... col_n;

col1, col2, ... col_n: These expressions must be included in GROUP BY clause.