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SQL how to increase or decrease one for a int column in one command
...gahooagahooa
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32
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Update MongoDB field using value of another field
..."name": { "$concat": ["$firstName", " ", "$lastName"]}}}
]
)
MongoDB 3.4+
In 3.4+ you can use $addFields and the $out aggregation pipeline operators.
db.collection.aggregate(
[
{ "$addFields": {
"name": { "$concat": [ "$firstName", " ", "$lastName" ] }
}},
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Difference between this and self in self-type annotations?
...n javascript]
– Ustaman Sangat
Jul 13 '13 at 15:20
4
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How do you write a migration to rename an ActiveRecord model and its table in Rails?
...had to go and rename the model declaration file manually.
Edit:
In Rails 3.1 & 4, ActiveRecord::Migration::CommandRecorder knows how to reverse rename_table migrations, so you can do this:
class RenameOldTableToNewTable < ActiveRecord::Migration
def change
rename_table :old_table_nam...
How do I find the duplicates in a list and create another list with them?
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34 Answers
34
Active
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Creating a simple XML file using python
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314
These days, the most popular (and very simple) option is the ElementTree API,
which has been i...
What is the default form HTTP method?
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173
It's GET.
Take a look W3C Superceded Recommendation 17.3 The FORM element.
Excerpt:
<!ATT...
Parcelable where/when is describeContents() used?
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Mithun
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answered Feb 6 '11 at 17:09
OgnyanOgnyan
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Creating NSData from NSString in Swift
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361
In Swift 3
let data = string.data(using: .utf8)
In Swift 2 (or if you already have a NSSt...
How to get a specific version of a file in Mercurial?
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153
I think you want hg revert -r<rev> <file> (this will change that file to be as it wa...