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narayana arya

Joined: Dec 12, 2005
Posts: 12
Does anybody explain or send link about joins (inner,self,...) detailly..
Maximilian Xavier Stocker
Ranch Hand

Joined: Sep 20, 2005
Posts: 381
In short JOINS join two tables together. For how and what exactly happens this is kind of vendor specific. I mean one can describe some theory but to put into practice you need to write the right JOIN for your Database. What database are you using?
Ranch Hand

Joined: Nov 22, 2008
Posts: 18944
Inner Join: to get the same tuples from different relations

Outer Joins: NEVER used alone.
  • Left (Outer) Join: to get the tuples that match + the ones that exist on the left relation even there does not exist any correspondent on the right relation
  • Right (Outer) Join: lokk at the above definition, and convert.
  • Full (Outer) Join: get really all the tuples; from both relations

  • Michael Duffy
    Ranch Hand

    Joined: Oct 15, 2005
    Posts: 163
    Originally posted by naranayana vijaya:
    Does anybody explain or send link about joins (inner,self,...) detailly..

    There's a great Wiki entry that explains it nicely:

    I agree. Here's the link:
    subject: joins
    It's not a secret anymore!