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How do I delete a fixed number of rows with sorting in PostgreSQL?
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You could try using the ctid:
DELETE FROM logtable
WHERE ctid IN (
SELECT ctid
FROM logtable
ORDER BY timestamp
LIMIT 10
)
The ctid is:
The physical location of the row version within its table. Note that although the ctid can be used to locate the...
PHP function to make slug (URL string)
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sanitize is a strange, forgettable function name to generate a slug.
– rybo111
Jul 3 '15 at 13:52
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How can I find out what FOREIGN KEY constraint references a table in SQL Server?
I am trying to drop a table but getting the following message:
15 Answers
15
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How to combine two or more querysets in a Django view?
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If merging querysets from the same table to perform an OR query, and have duplicated rows you can eliminate them with the groupby function: from itertools import groupby unique_results = [rows.next() for (key, rows) in groupby(result_list, key=lambda obj: obj...
What requests do browsers' “F5” and “Ctrl + F5” refreshes generate?
...trol by adding "Pragma: No-cache" when you pressed CTRL-F5.
Edit: Updated table
The table below is updated with information on what will happen when the browser's refresh-button is clicked (after a request by Joel Coehoorn), and the "max-age=0" Cache-control-header.
Updated table, 27 September 20...
CUDA incompatible with my gcc version
...l directory and then make symbolic links to the supported gcc version executables. Pass that local directory to nvcc via the --compiler-bindir option, and you should be able to compile CUDA code without affecting the rest of your system.
EDIT:
Note that this question, and answer, pertain to CUDA...
Client-server synchronization pattern / algorithm?
...g every change (insert, update or delete) from any device into a "history" table. So if, for example, someone changes their phone number in the "contact" table, the system will edit the contact.phone field, and also add a history record with action=update, table=contact, field=phone, record=[contact...
Meaning of Open hashing and Closed hashing
... us the index (aka. address) at which an object will be stored in the hash table is not completely determined by its hash code. Instead, the index may vary depending on what's already in the hash table.
The "closed" in "closed hashing" refers to the fact that we never leave the hash table; every...
In SQL, what's the difference between count(column) and count(*)?
...column) does not
[edit] added this code so that people can run it
create table #bla(id int,id2 int)
insert #bla values(null,null)
insert #bla values(1,null)
insert #bla values(null,1)
insert #bla values(1,null)
insert #bla values(null,1)
insert #bla values(1,null)
insert #bla values(null,null)
se...
How to avoid mysql 'Deadlock found when trying to get lock; try restarting transaction'
I have a innoDB table which records online users. It gets updated on every page refresh by a user to keep track of which pages they are on and their last access date to the site. I then have a cron that runs every 15 minutes to DELETE old records.
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