thisisfutile (9/11/2012)
Luis Cazares (9/10/2012)
CELKO (9/9/2012)
The correct terms are "preserved table " and "unpreserved table" ...Can you explain us these terms? I can't find any reference on the web.
While I'm sure Joe has a deeper, ANSI definition for these terms, I believe their simplest usage is as a reference point. In a LEFT join the LEFT table is the preserved table and the RIGHT is unpreserved. The reverse would be true in a RIGHT join. So in discussion it doesn't matter if we're talking about LEFT or RIGHT joins, we'll know which table is which using these two terms. Like in a car, we don't reference left and right sides because that's relevant to whether or not I'm looking at it from the back or from the front. Of course, referencing driver-side and passenger-side is different based on the country you live in. Now that I think about it, like boats, I'm all for using port and starboard for cars. 😛
There you go. In a LEFT OUTER JOIN from now on we will call the left table the "driver's side" or "port" table and the right one the "passenger side" or "starboard" table. Reverse of course for a RIGHT join. :hehe:
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