I have looked through Python Database API Specification v2.0, but can
not find any reference to the number of records processed in a select
query.
I know I can get the number of records returned with cursor.rowcount,
but I want to know the number of records processed.
I suppose the info is in one of the internal tables, but I can not
find any info on that, because phpMyAdmin shows the number of rows in
a table.
I suppose I could use count(*), but would that process all the
records, which would seem a bit silly.
What is the best method ?
Richard
4  1715 
On Wed, 2008-02-06 at 18:53 -0500, Steve Holden wrote:
If you mean the number of (say) rows updated by a SQL UPDATE statement,
the DB API does not provide any way to access that information
It doesn't? Isn't that what cursor.rowcount does?
--
Carsten Haese http://informixdb.sourceforge.net
On Wed, 2008-02-06 at 14:51 -0800, mcl wrote:
I have looked through Python Database API Specification v2.0, but can
not find any reference to the number of records processed in a select
query.
I know I can get the number of records returned with cursor.rowcount,
but I want to know the number of records processed.
I suppose the info is in one of the internal tables, but I can not
find any info on that, because phpMyAdmin shows the number of rows in
a table.
I suppose I could use count(*), but would that process all the
records, which would seem a bit silly.
What is the best method ?
Please define what you mean by "processed". If you simply need to know
how many rows are in a table, "select count(*) from that_table" is the
obvious solution. If the database engine is sufficiently intelligent, it
won't have to read the data in every single row to count the rows.
If that's not what you're looking for, please feel free to be more
specific about what you need to achieve.
--
Carsten Haese http://informixdb.sourceforge.net
On Feb 7, 12:19 am, Carsten Haese <cars...@uniqsys.comwrote:
On Wed, 2008-02-06 at 14:51 -0800, mcl wrote:
I have looked through Python Database API Specification v2.0, but can
not find any reference to the number of records processed in a select
query.
I know I can get the number of records returned with cursor.rowcount,
but I want to know the number of records processed.
I suppose the info is in one of the internal tables, but I can not
find any info on that, because phpMyAdmin shows the number of rows in
a table.
I suppose I could use count(*), but would that process all the
records, which would seem a bit silly.
What is the best method ?
Please define what you mean by "processed". If you simply need to know
how many rows are in a table, "select count(*) from that_table" is the
obvious solution. If the database engine is sufficiently intelligent, it
won't have to read the data in every single row to count the rows.
If that's not what you're looking for, please feel free to be more
specific about what you need to achieve.
--
Carsten Haesehttp://informixdb.sourceforge.net
Thanks for all the helpful replies.
If you think Count(*) is intelligent, then that is the easy answer. I
will attempt to do some timings.
I did mean number of rows in a table - by processed.
On Wed, 2008-02-06 at 21:35 -0500, Steve Holden wrote:
Carsten Haese wrote:
On Wed, 2008-02-06 at 18:53 -0500, Steve Holden wrote:
If you mean the number of (say) rows updated by a SQL UPDATE statement,
the DB API does not provide any way to access that information
It doesn't? Isn't that what cursor.rowcount does?
When it works, yes. Perhaps I should have said that the method provided
by the DB API isn't reliably implemented (for example, on SQL Server
2000 via mx.ODBC it would use a forward cursor which had no predictive
ability about its contents).
Yes, and the same will happen with Informix on a SELECT statement, for
pretty much the same reason. However, you have claimed that the number
of rows updated by an UPDATE statement is not provided, and I have yet
to see a DB-API implementation that doesn't set cursor.rowcount
correctly after executing an UPDATE statement. (The spec doesn't require
that the rowcount be set reliably after an update, but any sane database
engine ought be able to tell you how many rows it touched in an update!)
Anyway, as you said, the point is moot, I just wanted to make sure we're
all on the same page.
--
Carsten Haese http://informixdb.sourceforge.net This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics
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