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Possibility of duplicate Mongo ObjectId's being generated in two different collections?
...hat "almost certainly" means.
Long Answer
The BSON Object ID's generated by Mongo DB drivers are highly likely to be unique across collections. This is mainly because of the last 3 bytes of the ID, which for most drivers is generated via a static incrementing counter. That counter is collection-in...
Is there a way to list open transactions on SQL Server 2000 database?
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You can get all the information of active transaction by the help of below query
SELECT
trans.session_id AS [SESSION ID],
ESes.host_name AS [HOST NAME],login_name AS [Login NAME],
trans.transaction_id AS [TRANSACTION ID],
tas.name AS [TRANSACTION NAME],tas.transaction_begin_tim...
Check Whether a User Exists
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You can also check user by id command.
id -u name gives you the id of that user.
if the user doesn't exist, you got command return value ($?)1
And as other answers pointed out: if all you want is just to check if the user exists, use if with id dire...
How to get last inserted row ID from WordPress database?
...cause a problem if two records were inserted at almost the exact same time by two different processes? Both processes could insert at the same time (or close enough to the same time) so that the auto_increment would return the same number for both processes.
– Michael Khalili
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MySQL COUNT DISTINCT
...ite
From cp_visits
Where ts >= DATE_SUB(NOW(), INTERVAL 1 DAY)
Group By site_id
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Rails :include vs. :joins
...was changed to use multiple queries in some circumstances. This blog post by Fabio Akita has some good information on the change (see the section entitled "Optimized Eager Loading").
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Django ManyToMany filter()
... User.objects.filter(zones__in=[<id1>])
# filtering on a few zones, by id
users_in_zones = User.objects.filter(zones__in=[<id1>, <id2>, <id3>])
# and by zone object (object gets converted to pk under the covers)
users_in_zones = User.objects.filter(zones__in=[zone1, zone2, z...
Understanding Python's “is” operator
...ually wrong! Thanks for pointing that out @martijn-pieters ! I should know by now never to post code without testing it! >>> x=1.0; y=1.0 >>> x is y True >>> x=1.0 >>> y=1.0 >>> x is y False
– Magnus Lyckå
Sep 26 '...
Oracle SQL: Update a table with data from another table
...ltiple times for some/all records (not clean). Secondly: there is no order by clause so this will occur in an unpredictable manner (i.e. last value in unordered data wins). Thirdly: It will be much slower. Assuming the outcome of the for loop was intended, the original subselect could have been rewr...
How to continue a Docker container which has exited
...created. -q merely suppresses other info (bedsides the id) usually output by `docker ps`. ---- note: Backtick is not a quotation sign, it has a very special meaning. Everything you type between backticks is evaluated (executed) by the shell before the main command - unix.stackexchange.com/que...