LEFT JOIN vs. LEFT OUTER JOIN in SQL Server
As per the documentation: FROM (Transact-SQL): The keyword OUTER is marked as optional (enclosed in square brackets). In this specific case, whether you specify OUTER or not makes no difference. Note that while the other elements of the join clause is also marked as optional, leaving them out will make a difference. For instance, the entire type-part of the JOIN clause is optional, in which case … Read more