Go Premium for a chance to win a PS4. Enter to Win

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 963
  • Last Modified:

In what scenario should I using cross outer join?

When can I user cross outer join in SQL Server?
0
RajG1978
Asked:
RajG1978
2 Solutions
 
Koen Van WielinkIT ConsultantCommented:
A cross join produces the cartesian product of the tables you combine (all rows from table 1 x all rows from table 2). One application I can think of is if you're trying to analyze certain scenarios, and you need to have a list of all possible combinations that make up a scenario.
For example, say that you have a list of motherboard parts in 1 table, and a list of CPU parts in another table, and you want to generate a list of all the possible combinations of motherboards and CPU's (e.g. for a price list) you can use a cross join on both tables to do this.
If you use a cross join but put a link between the 2 tables in the WHERE clause it will behave like a normal inner join.
More info here:
http://technet.microsoft.com/en-us/library/ms190690(v=sql.105).aspx
0
 
magarityCommented:
When you have a requirement that needs that functionality; not sure how anyone here could answer that for you. Typically for a matrix of every combination: suppose you want a matrix of every color for every dress for every size:
select color, size, dress from color_table, size_table, dress_table
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now