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Find distinct records that are not distinct
Message
De
17/11/2007 16:37:45
 
 
À
16/11/2007 17:44:36
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Divers
Thread ID:
01269536
Message ID:
01269718
Vues:
18
>>>Huh? I know, its a strange subject line. Here's my problem. Through something of a snafu we have about 600 records in a table that are improper duplicates of other records. We want to remove them. This would be easy with select distinct EXCEPT that one field "sequence" was provided to create a unique sequence number for each record. So, they are all distinct because they all have different sequence numbers. I can get around this by selecting into a cursor, deleting the sequence numbers, and then selecting dist from the cursor. This gives me the truly distinct records albeit without the sequence numbers. Now I need to put the original sequence numbers back. Any ideas on how to do this?
>>
>>
>>Can you do something like:
>>
>>Select max(seqfield), field1, field2, field3, etc from table into cursor crsrname group by field1, field2, field3, etc
>>
>>Will that give you your distinct records?
>
>On the surface at least that seems to work. Thank you very much. I've never really understood the GROUP BY clause. Is there a simple explanation for dummies of what it does?
>
>Thanks again

I don't know how 'dummiefied' this is, but try this: http://publib.boulder.ibm.com/infocenter/db2v7luw/index.jsp?topic=/com.ibm.db2v7.doc/db2y0/db2y025.htm

When you get there, on the left, under 'Chapter 4', select grouping (at the bottom of the chapter 4 headings).
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