On Nov 12, 2007 10:41 AM, Charles Mortell <cmortell@xxxxxxxxxxxx> wrote: > Using PG 8.0 on Windows, I have a table 'business_list' with a two column > primary key. It's a linking table and it's primary keys are the keys from > the two tables I am linking: item_id and business. > Should I be able to update one of those primary key fields? > > Here is the SQL: > UPDATE projectdata.business_list SET business = 13 Where item_id = 1 and > business = 7; > > It causes the following error: ERROR: duplicate key violates unique > constraint "data_business_list_pkey" This is not a complete example. What are the two fields in your pkey? I'm guessing business and list. If list is one, what are the values for list in your table where business=13 and business=7. If you look those up you should see one there with 13 for business and whatever for list that is causing this problem. > Is something wrong or is it just not possible to update a two-column primary > key? Good lord no. You're just making a simple mistake is all. Here, look: create table test (a int, b int, c text, primary key (a,b)) insert into test values (1,2,'abc'); insert into test values (2,2,'abc'); -- Now I update a without checking on b... update test set a=1 where a=2; ERROR: duplicate key violates unique constraint "test_pkey" ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
