On 7 September 2011 00:55, salah jubeh
<s_jubeh@yahoo.com> wrote:
Hello Thom.
what is the meaning of
select table_name from table_name
Also is this a common behavior of all Databases i.e. oracle , Microsoft ,...etc . i.e is this is the standard behavior
I think this is a good way to find duplicates in general, I will write a routine to compare all the columns by excluding the primary key which is serial
Thanks in advance
Well I just put table_name as a placeholder for the actual name of the table you wish to remove duplicates from.
No, you can't run this query on other databases, particularly because ctids are specific to PostgreSQL. Other databases will use different methods to this one, if they have any at all. With Oracle you'd probably use ROWNUM somehow, and SQL Server will likely use some awful multi-query technique involving creating temporary tables, copying distinct rows from the duplicate set to another table, deleting it from the original and copying back. Can't say for sure though since I haven't used it in quite a while.
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Thom Brown
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