Math function -ror
From Sandoz
a == b : a égal b (attention, contrairement à PHP par exemple, '42' == 42 renverra false)
a != b : a différent de b
a < b : a strictement inférieur à b
a > b : a strictement supérieur à b
a <= b : a inférieur ou égal à b
a >= b : a supérieur ou égal à b
Consider a table object called Person. This table is having fields like age, first_name, last_name and salary.
Following will return average age of all the employee.
Person.average :age
Following will return maximum age of the employee.
Person.maximum :age
Following will return minimum age of the employee.
Person.minimum :age
Follwoing will return sum of salaries of all the employees.
Person.sum :salary, :group => :last_name
Following will count the number of records having age more than 26.
Person.count(:conditions => "age > 26")
Following count total number of records.
Person.count
