Scott, To find dupe batch values SELECT batch, COUNT(batch) AS Cnt FROM qa GROUP BY batch HAVING Cnt > 1; Peter Brawley http://www.artfulsoftware.com ----- Scott Hamm wrote: Sorry for the confusion. I don't mean a duplicated records, but to find duplicated Batch where two different operators worked on a single batch (one started off, then another one to finish the batch) and a single reviewer to review a batch. I need a list that lists duplicated Batches with different operators that worked on that batch.For example: (for clarification) SELECT ID, Batch, KeyDate, OperatorID, QAID, NTID FROM QA WHERE Batch='439584414'; ID Batch KeyDate OperatorID QAID NTID 90577 439584414 2004-10-03 00:00:00 2661 5334 JulieAnt 90575 439584414 2004-10-03 00:00:00 5657 5334 JulieAnt On Apr 5, 2005 10:54 AM, Rhino <[EMAIL PROTECTED]> wrote:----- Original Message ----- From: "Scott Hamm" <[EMAIL PROTECTED]> To: "Mysql" <mysql@lists.mysql.com> Sent: Tuesday, April 05, 2005 10:05 AM Subject: Duplicated recordsHere is my novice question: I need to find duplicates in "Batch" category when I issued this query: SELECT * FROM QA WHERE Batch=439584414; Result: 90577 1 2661 5334 JulieAnt 25 5 5 439584414 2004-10-03 00:00:00 2004-10-03 00:00:00 0 90575 1 5657 5334 JulieAnt 25 5 5 439584414 2004-10-03 00:00:00 2004-10-0300:00:00 0How do I issue a query that finds duplicated Batch number?First of all, I think you made a mistake when putting this data into your note, a mistake which is compounded by the wrapping that the email program did. I *think* you meant to display two rows with the '90577' value at the end of the second row, not before the first row. This makes the example a bit confusing and hard to follow. The two rows you provide in your example are not duplicates of each other. Even assuming that the '90577' actually belongs at the end of the second row rather than the start of the first row, the two rows are different: the first row ends in '90575', not '90577' and the second value in each row is also different: '2661' and '5657'. Therefore, you're not really trying to find duplicate records because a duplicate row would be one that is identical in every column, not just identical in several columns. I hope that doesn't sound like I am splitting hairs; maybe I am. ;-) Anyway, the standard method for finding duplicates of rows goes like this and can be adapted for your situation. Let's say that you have a table called Foo with columns foo1, foo2, and foo3 and you want to find all of the duplicate rows in the table, i.e. any row whose foo1, foo2, and foo3 value is identical to the foo1, foo2, and foo3 value of another table. You would write this query: select foo1, foo2, foo3, count(*) as num from Foo1 group by foo1, foo2, foo3 having num > 1 order by num; Your result might look like this: foo1 foo2 foo3 num Daffy D Duck 1 Bugs B Bunny 1 Elmer A Fudd 3 This result means that Daffy D Duck and Bugs B Bunny each occur once in the table but Elmer A Fudd occurs three times. In the case you mentioned in your email, where the rows aren't complete duplicates of one another, just write the query so that you omit the columns which are allowed to be different. In your case, that would appear to be all but the second and last columns. However, I think if you get to the point of having duplicate records in a table when you don't want them, finding them is like shutting the barn door after the horse is already gone. I think you need to reconsider your design, specifically your primary key, and change that primary key to *PREVENT* the duplicate keys in the first place. For instance, in the case of the Foo1 table, I can prevent duplicate rows by choosing a good primary key; in this case I would choose the combination of all three columns in the table; that would ensure that I never stored more than 1 person named Elmer A Fudd. [Actually, that's not a great example! It might be perfectly valid to have two people named Elmer A Fudd - or John A Smith - so I probably need to add additional columns to my table to ensure that the rows are unique; something like Social Security Number which is (supposed to be) unique would be ideal for this purpose.] Rhino -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.9.2 - Release Date: 05/04/2005 |
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