Definition of Order by (sql)

An ORDER BY clause in SQL specifies that a SQL SELECT statement returns a result set with the rows being sorted by the values of one or more columns. The sort criteria does not have to be included in the result set. The sort criteria can be expressions, including - but not limited to - column names, user-defined functions, arithmetic operations, or CASE expressions. The expressions are evaluated and the results are used for the sorting, i.e. the values stored in the column or the results of the function call.