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Finding duplicate values in a SQL table
...ly group on both of the columns.
Note: the older ANSI standard is to have all non-aggregated columns in the GROUP BY but this has changed with the idea of "functional dependency":
In relational database theory, a functional dependency is a constraint between two sets of attributes in a relation...
How to convert a char to a String?
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@BinkanSalaryman using javac 1.8.0_51-b16 and then javap to decompile, I see the constructor/method calls I have in the answer. What are you using?
– Paul Bellora
Jul 24 '15 at 2:55
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Struct constructor: “fields must be fully assigned before control is returned to the caller.”
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@RogerWillcocks, just call the default constructor then: public YourStruct(some params) : this() (see vittore's answer)
– Thomas Levesque
Nov 27 '12 at 2:25
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PHP Fatal error: Call to undefined function json_decode()
Apache is logging PHP Fatal error: Call to undefined function json_decode() . After some googling, it seems this problem is a result of not having the latest version of php. Oddly, running php --version ouputs
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Join/Where with LINQ and Lambda
...re post.ID == id
select new { Post = post, Meta = meta };
If you're really stuck on using lambdas though, your syntax is quite a bit off. Here's the same query, using the LINQ extension methods:
var id = 1;
var query = database.Posts // your starting point - table in the "from" statement
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Why is the minimalist, example Haskell quicksort not a “true” quicksort?
... two beautiful aspects:
Divide and conquer: break the problem into two smaller problems.
Partition the elements in-place.
The short Haskell example demonstrates (1), but not (2). How (2) is done may not be obvious if you don't already know the technique!
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Pandas: drop a level from a multi-level column index?
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@yoonghm It is there, you are probably just calling it on columns that don't have a multi-index
– matt harrison
Dec 18 '18 at 14:59
1
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Find objects between two dates MongoDB
...being before "Jan Sun 01.01.1000"). It would probably make sense to format all date data into the MongoDB format, which I think is just plain JavaScript Date.
– ponzao
May 31 '10 at 16:47
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How do I compare two hashes?
...=> [["c", 3]]
Hash[*difference.flatten]
=> {"c"=>3}
Doing it all in one operation and getting rid of the difference variable:
Hash[*(
(hash3.size > hash1.size) \
? hash3.to_a - hash1.to_a \
: hash1.to_a - hash3.to_a
).flatten]
=> {"c"=>3}
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Use of undeclared identifier 'kUTTypeMovie'
... MobileCoreServices
Open Video Camera
@IBAction func openVideoCamera(_ sender: Any) {
if UIImagePickerController.isSourceTypeAvailable(.camera) {
let imagePicker = UIImagePickerController()
imagePicker.delegate = self
imagePicker.sourceType = .camera
imageP...