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ERROR 1452: Cannot add or update a child row: a foreign key constraint fails
...2. Cannot add or update a child row: a foreign key constraint fails essentially means that, you are trying to add a row to your Ordrelinje table for which no matching row (OrderID) is present in Ordre table.
You must first insert the row to your Ordre table.
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Include only certain file types when searching in Visual Studio
...e used the same variable name in a JavaScript file, I have to wade through all those search results too. This gets even worse when the text I'm looking for is also used in a third-party JavaScript library that we've brought into the project: this can result in hundreds of search results.
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SQLAlchemy: Creating vs. Reusing a Session
Just a quick question: SQLAlchemy talks about calling sessionmaker() once but calling the resulting Session() class each time you need to talk to your DB. For me that means the second I would do my first session.add(x) or something similar, I would first do
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Get Character value from KeyCode in JavaScript… then trim
... get garbage. The problem is that keyCode does not correspond to ASCII for all characters. The ASCII character for semicolon is 59. Same issue is true of every special character, keyCode does NOT return the right code for String.fromCharCode().
– Alexander Tsepkov
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When would you use the different git merge strategies?
...s:
Recursive
Recursive is the default for non-fast-forward merges. We're all familiar with that one.
Octopus
I've used octopus when I've had several trees that needed to be merged. You see this in larger projects where many branches have had independent development and it's all ready to come to...
How to convert wstring into string?
...e <locale>
#include <vector>
int main() {
std::setlocale(LC_ALL, "");
const std::wstring ws = L"ħëłlö";
const std::locale locale("");
typedef std::codecvt<wchar_t, char, std::mbstate_t> converter_type;
const converter_type& converter = std::use_facet<converter...
Which cryptographic hash function should I choose?
...ese properties. A hash function for securing passwords on a server will usually only require preimage resistance, while message digests require all three.
It has been shown that MD5 is not collision resistant, however, that does not preclude its use in applications that do not require collision res...
How does the ARM architecture differ from x86? [closed]
Is the x86 Architecture specially designed to work with a keyboard while ARM expects to be mobile? What are the key differences between the two?
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Can an abstract class have a constructor?
...hardcodes the value 2. The concrete class TimesWhat has a constructor that allows the caller to specify the value.
Abstract constructors will frequently be used to enforce class constraints or invariants such as the minimum fields required to setup the class.
NOTE: As there is no default (or no...
Vim delete blank lines
... Thanks soulmerge. This is my favorite answer, since it actually explains what the :g command does.
– Tim Swast
Aug 15 '11 at 19:03
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