IntegrityError duplicate key value violates unique

Question

I'm following up in regards to a question that I asked earlier in which I sought to seek a conversion from a goofy/poorly written mysql query to postgresql. I believe I succeeded with that. Anyways, I'm using data that was manually moved from a mysql database to a postgres database. I'm using a query that looks like so:

  """
  UPDATE krypdos_coderound cru

  set is_correct = case 
      when t.kv_values1 = t.kv_values2 then True 
      else False 
      end

  from 

  (select cr.id, 
    array_agg(
    case when kv1.code_round_id = cr.id 
    then kv1.option_id 
    else null end 
    ) as kv_values1,

    array_agg(
    case when kv2.code_round_id = cr_m.id 
    then kv2.option_id 
    else null end 
    ) as kv_values2

    from krypdos_coderound cr
     join krypdos_value kv1 on kv1.code_round_id = cr.id
     join krypdos_coderound cr_m 
       on cr_m.object_id=cr.object_id 
       and cr_m.content_type_id =cr.content_type_id 
     join krypdos_value kv2 on kv2.code_round_id = cr_m.id

   WHERE
     cr.is_master= False
     AND cr_m.is_master= True 
     AND cr.object_id=%s 
     AND cr.content_type_id=%s 

   GROUP BY cr.id  
  ) t

where t.id = cru.id
    """ % ( self.object_id, self.content_type.id)
  )

I have reason to believe that this works well. However, this has lead to a new issue. When trying to submit, I get an error from django that states:

IntegrityError at (some url): 
duplicate key value violates unique constraint "krypdos_value_pkey"

I've looked at several of the responses posted on here and I haven't quite found the solution to my problem (although the related questions have made for some interesting reading). I see this in my logs, which is interesting because I never explicitly call insert- django must handle it:

   STATEMENT:  INSERT INTO "krypdos_value" ("code_round_id", "variable_id", "option_id", "confidence", "freetext")
   VALUES (1105935, 11, 55, NULL, E'') 
   RETURNING "krypdos_value"."id"

However, trying to run that results in the duplicate key error. The actual error is thrown in the code below.

 # Delete current coding         CodeRound.objects.filter(object_id=o.id,content_type=object_type,is_master=True).delete()
  code_round = CodeRound(object_id=o.id,content_type=object_type,coded_by=request.user,comments=request.POST.get('_comments',None),is_master=True)
  code_round.save()
  for key in request.POST.keys():
    if key[0] != '_' or key != 'csrfmiddlewaretoken':
      options = request.POST.getlist(key)
      for option in options:
        Value(code_round=code_round,variable_id=key,option_id=option,confidence=request.POST.get('_confidence_'+key, None)).save()  #This is where it dies
  # Resave to set is_correct
  code_round.save()
  o.status = '3' 
  o.save(

I've checked the sequences and such and they seem to be in order. At this point I'm not sure what to do- I assume it's something on django's end but I'm not sure. Any feedback would be much appreciated!

Answer 1

If you want to reset the PK on all of your tables, like me, you can use the PostgreSQL recommended way:

SELECT 'SELECT SETVAL(' ||
       quote_literal(quote_ident(PGT.schemaname) || '.' || quote_ident(S.relname)) ||
       ', COALESCE(MAX(' ||quote_ident(C.attname)|| '), 1) ) FROM ' ||
       quote_ident(PGT.schemaname)|| '.'||quote_ident(T.relname)|| ';'
FROM pg_class AS S,
     pg_depend AS D,
     pg_class AS T,
     pg_attribute AS C,
     pg_tables AS PGT
WHERE S.relkind = 'S'
    AND S.oid = D.objid
    AND D.refobjid = T.oid
    AND D.refobjid = C.attrelid
    AND D.refobjsubid = C.attnum
    AND T.relname = PGT.tablename
ORDER BY S.relname;

After running this query, you will need to execute the results of the query. I typically copy and paste into Notepad. Then I find and replace "SELECT with SELECT and ;" with ;. I copy and paste into pgAdmin III and run the query. It resets all of the tables in the database. More "professional" instructions are provided at the link above.

Answer 2

I had the same issue. I had an existing table in my "inventory" app and I wanted to add new records in django admin and I got these messages:

Duplicate key value violates unique constraint "inventory_part_pkey" DETAIL: Key (part_id)=(1) already exists.

As mentioned before run the code bellow to get generate an SQL command to reset the id-s:

python manage.py sqlsequencereset inventory

In my case python manage.py sqlsequencereset MyApp | python manage.py dbshell was not working

• So I copied the generated SQL statement.
• Then opened pgAdmin for postgreSQL and opened my db.
• Clicked on the 6. icon (Execute arbitrary SQL queries)
• Copied the statement what was generated.

In my case it was:

BEGIN; SELECT setval(pg_get_serial_sequence('"inventory_signup"','id'), coalesce(max("id"), 1), max("id") IS NOT null) FROM "inventory_signup"; SELECT setval(pg_get_serial_sequence('"inventory_supplier"','id'), coalesce(max("id"), 1), max("id") IS NOT null) FROM "inventory_supplier"; COMMIT;

Executed it with F5.

This fixed all my tables and finally adding new records to the end not trying to add it to id = 1 any more.

Answer 3

In addition to zapphods answer:

In my case the indexing was indeed incorrect, since I had deleted all migrations, and the database probably 10-15 times when developing as I wasn't in the stage of migrating anything.

I was getting an IntegrityError on finished_product_template_finishedproduct_pkey

Reindex the table and restart runserver:

I was using pgadmin3 and for whichever index was incorrect and throwing duplicate key errors I navigated to the constraints and reindexed.

And then reindexed.

Answer 4

I was getting the same error as the OP.

I had created some Django models, created a Postgres table based on the models, and added some rows to the Postgres table via Django Admin. Then I fiddled with some of the columns in the models (changing around ForeignKeys, etc.) but had forgotten to migrate the changes.

Running the migration commands solved my problem, which makes sense given the SQL answers above.

To see what changes would be applied, without actually applying them:
python manage.py makemigrations --dry-run --verbosity 3

If you're happy with those changes, then run:
python manage.py makemigrations

Then run:
python manage.py migrate

Answer 5

If you have manually copied the databases, you may be running into the issue described here.

Answer 6

I encountered this error because I was passing extra arguments to the save method in the wrong way.

For anybody who encounters this, try forcing UPDATE with:

instance_name.save(..., force_update=True)

If you get an error that you cannot pass force_insert and force_update at the same time, you're probably passing some custom arguments the wrong way, like I did.