There is plenty of data in tables that could be the same data available for multiple records. We may want to know these details and perform some action.
Considering the following example.
+-------------------+| ID | Name |+-------------------+| 1 | Alberto || 2 | Barton || 3 | Clarion || 4 | David || 5 | Clarion || 6 | David || 7 | Clarion |+-------------------+Now, using the COUNT function along with GROUB BY, we arrive at the magic data for which we were searching. SELECT NAME, COUNT(Name) FROM Employee GROUP BY Name;
+---------------------------+| Name | Count(Name) |+---------------------------+| Alberto | 1 || Barton | 1 || Clarion | 3 || David | 2 |+---------------------------+ 
