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How can I retrieve records X to Y using DBI?

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Contributed by BBQ on May 01, 2000 at 11:25 UTC
Q&A  > database programming


Description:

How does one go about selecting X number of rows on a query (e.g. with MySQL)? The desired effect would be to return results from 0-20, then 20-40, and so on.

Answer: How to display from X to Y records using DBI?
contributed by btrott

I'll expand on what chromatic wrote, because the LIMIT keyword can do even more than just that. :) In addition to specifying the max number of records to return, you can specify an offset of where to start in the records being returned. The syntax is

[LIMIT [offset,] rows]
So, for example, to view records 10-35, do this:
select log_id from log_id limit 10,25
Pretty neat! Consult the MySQL SELECT docs for more details and tips.
Answer: How to display from X to Y records using DBI?
contributed by chromatic

You could use the SQL command LIMIT: SELECT * from presidents WHERE terms > 2 LIMIT 10; You can also use the DBI method fetchall_arrayref(), which will return a reference to a list of rows. Use an array slice to get at the ones you want:

# prepare and execute statement my $array_ref = $sth->fetchall_arrayref(); # we want 0 through 20 foreach my $row (@$array_ref[0 .. 20]) { # do something }

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