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Do you have a unique key on
site,variable?
If not, what do you want in the treatment column if there are rows for both treatments X and Y or 2 Xs for a specific site and variable? If your data makes sense, you can pivot table t1 and then full join t2. Sim On 12/29/2012 11:45 PM, Kirk Wythers wrote: I have been given an interesting problem to solve in a postgres db. I was given two tables t1: site treatment variable id (pk) ------------------------------------------------------------- A X BLUE 1A B Y RED 2B A Y GREEN 3A t2: rowid (pk) timestamp BLUE RED GREEN ----------------------------------------------------------------------------------------- 1 1332493200 3.4 2.1 5.8 2 1332496800 3.2 2.0 5.8 3 1332500400 3.3 2.2 6.0 I need to combine the site and treatment information from t1 with the variable records in t2. I think I will have to combine these one variable at a time. Something like this (I'm not using the word join, because I don't think this is a join in the regular sense. It's more like some kind of crazy pivot table thing!): t3: rowid (pk) timestamp BLUE site treatment ------------------------------------------------------------------------------------- 1 1332493200 3.4 A X 2 1332496800 3.2 A X 3 1332500400 3.3 A X and then: t4 rowid (pk) timestamp RED site treatment ------------------------------------------------------------------------------------- 1 1332493200 2.1 B Y 2 1332496800 2.0 B Y 3 1332500400 2.2 B Y Is this even possible? |
