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08-07-2011, 01:18 PM #1
- Join Date
- Jul 2011
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how to avoid duplicate entry in database
hello .. can anyone help me in inserting a duplicate entry in database?
Actually i have a table "option" with 3 fields and two of them are set to primary key (composite). I have a poll descriptions in some other table (not concern here) and i have to put that poll's answers in table "option" and obviously when i insert data i should be like this
poll_id answer_id answer_des
1 1 myans_1
1 2 myans_2
1 3 myans_3
the above data means that there is a poll with id=1 and it has 3 answers.
first row is inserted easily but on second time it shows error of duplicate entry .. howdo i avoide it because i cannot remove the tag of primary key from "poll_id" and "field_id" .. Is there is any solution?
08-07-2011, 02:39 PM #2
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- Sep 2002
- Saskatoon, Saskatchewan
- Thanked 2,662 Times in 2,631 Posts
It sounds to me that the composite key is not actually in place, and only the poll_id is the primary.
Run a describe on the table in question. Does it list that both the poll_id and answer_id are of type PRI for their keys? If these check out and list that the composite is in place, then the problem is you simply already have a record of 1 and 2 in the database before inserting OR your code is not updating the answer_id correctly before trying to insert it so that the second entry is trying to go in as 1 and 1 instead of 1 and 2.
Last edited by Fou-Lu; 08-07-2011 at 02:41 PM.