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How to avoid mysql 'Deadlock found when trying to get lock; try restarting transaction'
...now() - INTERVAL 900 SECOND
To
DELETE FROM onlineusers
WHERE id IN (
SELECT id FROM onlineusers
WHERE datetime <= now() - INTERVAL 900 SECOND
ORDER BY id
) u;
Another thing to keep in mind is that mysql documentation suggest that in case of a deadlock the client should retry autom...
difference between variables inside and outside of __init__()
...
class meta(type):
def __new__(cls,name,bases,dicto):
# two chars missing in original of next line ...
if dicto['class_var'] == 'A':
print 'There'
class proxyclass(object):
class_var = 'A'
__metaclass__ = meta
...
...
...
Using Chrome, how to find to which events are bound to an element
...e Event you need
From the handler property, right click over function and select 'Show function definition'
You will now see the Event binding code
Click on the 'Pretty print' button for a more readable view of the code
sh...
Oracle SQL escape character (for a '&')
... table blah (x varchar(20));
insert into blah (x) values ('blah&amp');
select * from blah;
X
--------------------
blah&amp
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Oracle find a constraint
...
select * from all_constraints
where owner = '<NAME>'
and constraint_name = 'SYS_C00381400'
/
Like all data dictionary views, this a USER_CONSTRAINTS view if you just want to check your current schema and a DBA_CONSTRA...
Disabled form fields not submitting data [duplicate]
...entioned: READONLY does not work for <input type='checkbox'> and <select>...</select>.
If you have a Form with disabled checkboxes / selects AND need them to be submitted, you can use jQuery:
$('form').submit(function(e) {
$(':disabled').each(function(e) {
$(this).rem...
How can I add comments in MySQL?
...es of commenting are supported
Hash base single line commenting using #
Select * from users ; # this will list users
Double Dash commenting using --
Select * from users ; -- this will list users
Note : Its important to have single white space just after --
3) Multi line commenting using ...
How to convert timestamp to datetime in MySQL?
...
SELECT from_unixtime( TIMESTAMP( "2011-12-01", "22:01:23.048" ) ) doesn't work. why? using v5.6
– Janus Troelsen
Feb 4 '14 at 18:44
...
How do I use Linq to obtain a unique list of properties from a list of objects?
...
IEnumerable<int> ids = list.Select(x=>x.ID).Distinct();
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How to open a web server port on EC2 instance
...asn't immediately clear to me from the linked instructions, but you should select "Custom TCP". Otherwise you won't be able to change the port.
– KKOrange
Dec 12 '19 at 1:39
a...