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How to 'bulk update' with Django?
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Update:
Django 2.2 version now has a bulk_update.
Old answer:
Refer to the following django documentation section
Updating multiple objects at once
In short you should be able to use:
ModelClass.objects.filter(name='bar').update(name="foo")
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Is there an exponent operator in C#?
... @Justas I just testing that on .NET Core 2.1 and Math.Pow is now faster than the suggested alternative implementation.
– bytedev
Dec 19 '18 at 11:19
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When do we need curly braces around shell variables?
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{} is known as brace expansion. ${} is known as variable expansion. They do different things. I'd upvote you except for the no expansion bit.
– Spencer Rathbun
Jan 5 '12 at 21:52
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Why do you have to call .items() when iterating over a dictionary in Python?
...hen would you ever write a condition like this?
if (key, value) in dict:
Now it's not necessary that the in operator and for ... in operate over the same items. Implementation-wise they are different operations (__contains__ vs. __iter__). But that little inconsistency would be somewhat confusing ...
Calling method using JavaScript prototype
...he prototype. Your response forces me to create a factory and i'd like to know if there's any way to avoid that.
– R01010010
Dec 24 '14 at 3:09
10
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NodeJS: How to get the server's port?
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Express 4.x answer:
Express 4.x (per Tien Do's answer below), now treats app.listen() as an asynchronous operation, so listener.address() will only return data inside of app.listen()'s callback:
var app = require('express')();
var listener = app.listen(8888, function(){
console.lo...
Error: Jump to case label
...}
dostuff(i);
break;
}
case 2:
dostuff(123); // Now you cannot use i accidentally
}
Edit
To further elaborate, switch statements are just a particularly fancy kind of a goto. Here's an analoguous piece of code exhibiting the same issue but using a goto instead of a switc...
XAMPP, Apache - Error: Apache shutdown unexpectedly
...PP, and when I try to start my Apache server in the XAMPP Control Panel, I now get the following errors:
50 Answers
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What is the difference between “ is None ” and “ ==None ”
...mparison is implemented elementwise:
import numpy as np
a = np.zeros(3) # now a is array([0., 0., 0.])
a == None #compares elementwise, outputs array([False, False, False]), i.e. not boolean!!!
a is None #compares object to object, outputs False
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How do I execute inserts and updates in an Alembic upgrade script?
... teams[player.team_name]
session.commit()
# don't need team name now that team relationship is set
op.drop_column('players', 'team')
def downgrade():
bind = op.get_bind()
session = orm.Session(bind=bind)
# re-add the players.team column
op.add_column('players', sa.Co...