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How to pull a random record using Django's ORM?
...anager):
def random(self):
count = self.aggregate(count=Count('id'))['count']
random_index = randint(0, count - 1)
return self.all()[random_index]
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CASCADE DELETE just once
...cascade.
DELETE FROM some_child_table WHERE some_fk_field IN (SELECT some_id FROM some_Table);
DELETE FROM some_table;
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SQL SELECT speed int vs varchar
...your (say) 8-byte ints are longer than ascii varchars holding some textual IDs of avg length 3-4 chars. So, this answer - being imprecise and lacking any specific context or experimental results - doesn't really answer the question. Everyone knows that varchars are allowed to take much more space th...
Cookies vs. sessions
...hat time, I preferred cookies (and who does not like cookies?!) and just said: "who cares? I don't have any good deal with storing it in my server", so, I went ahead and used cookies for my bachelor graduation project. However, after doin' the big part of my app, I heard that for the particular case...
How to add a button to a PreferenceScreen?
I'm quite new to Android Development and just came across Preferences.
I found PreferenceScreen and wanted to create a login functionality with it. The only problem I have is that I don't know how I could add a "Login" button to the PreferenceScreen .
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SQL query to find record with ID not in another table
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Try this
SELECT ID, Name
FROM Table1
WHERE ID NOT IN (SELECT ID FROM Table2)
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Why am I getting a “401 Unauthorized” error in Maven?
...line it works, but then when you do it from a script it fails (because it didn't exist in the repository the first time around). Either publish using a different version number, or delete the old artefact on the server and republish.
The SNAPSHOTS repository (as opposed to the releases repository)...
When use getOne and findOne methods Spring Data JPA
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TL;DR
T findOne(ID id) (name in the old API) / Optional<T> findById(ID id) (name in the new API) relies on EntityManager.find() that performs an entity eager loading.
T getOne(ID id) relies on EntityManager.getReference() that perform...
ASP.NET MVC - Set custom IIdentity or IPrincipal
...hing fairly simple: in my ASP.NET MVC application, I want to set a custom IIdentity / IPrincipal. Whichever is easier / more suitable. I want to extend the default so that I can call something like User.Identity.Id and User.Identity.Role . Nothing fancy, just some extra properties.
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SQL Server: Is it possible to insert into two tables at the same time?
...ata_Table and Link_Table . The link table just contains two columns, the identity of an object record and an identity of a data record.
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