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differentiate null=True, blank=True in django
When we add a database field in django we generally write:
18 Answers
18
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How do I use cascade delete with SQL Server?
...o perform cascading delete in SQL Server when a record from T1 is deleted, all associated records in T2 also deleted.
8 An...
Can I concatenate multiple MySQL rows into one field?
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My need was to get ALL the data from one column. Don't use the GROUP BY clause to do this. Example : SELECT GROUP_CONCAT(emails SEPARATOR ', ') FROM users;
– Jonathan Bergeron
Jan 17 '14 at 14:04
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How to get Resource Name from Resource id
... wouldn't recommend use it if you use Proguard (minifyEnabled true), especially for getResources().getIdentifier(...
– user25
Jul 14 '18 at 22:54
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source of historical stock data [closed]
I'm trying to make a stock market simulator (perhaps eventually growing into a predicting AI), but I'm having trouble finding data to use. I'm looking for a (hopefully free) source of historical stock market data.
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How can I get pg_dump to authenticate properly
...ing host variable PGPASSWORD and .pgpass and neither of these two will allow me to authenticate to the database. I have chmod 'd .pgpass to appropriate permissions and also tried:
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MVVM in WPF - How to alert ViewModel of changes in Model… or should I?
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RaisePropertyChanged("ViewModelCopyOfSomeProperty");
}
But typically this is only needed if more than one object will be making changes to the Model's data, which is not usually the case.
If you ever have a case where you don't actually have a reference to your Model property to attach t...
How connect Postgres to localhost server using pgAdmin on Ubuntu?
I installed Postgres with this command
6 Answers
6
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advantage of tap method in ruby
...= User.new
user.username = "foobar"
user.save!
they would have to follow all the three lines and then recognize that it is just creating an instance named user.
If it were:
user = User.new.tap do |u|
u.username = "foobar"
u.save!
end
then that would be immediately clear. A reader would not...
How to link to apps on the app store
...C is here.
A SKStoreProductViewController object presents a store that allows the
user to purchase other media from the App Store. For example, your app
might display the store to allow the user to purchase another app.
From News and Announcement For Apple Developers.
Drive Customer...