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Why use multiple columns as primary keys (composite primary key)
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Your understanding is correct.
You would do this in many cases. One example is in a relationship like OrderHeader and OrderDetail. The PK in OrderHeader might be OrderNumber. The PK in OrderDetail might be OrderNumber AND LineNumber. ...
Change name of iPhone app in Xcode 4
... which is displayed below the app icon on the iPhone screen.
I use Xcode 4 and I have one target with keys:
11 Answers
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Bytecode features not available in the Java language
...s, however:
The ACC_SUPER flag:
This is a flag that can be set on a class and specifies how a specific corner case of the invokespecial bytecode is handled for this class. It is set by all modern Java compilers (where "modern" is >= Java 1.1, if I remember correctly) and only ancient Java compil...
Angular HttpPromise: difference between `success`/`error` methods and `then`'s arguments
...mment below, success() does return the original promise. I'll not change; and leave it to OP to edit.
The major difference between the 2 is that .then() call returns a promise (resolved with a value returned from a callback) while .success() is more traditional way of registering callbacks and d...
static allocation in java - heap, stack and permanent generation
I have been lately reading a lot on memory allocation schemes in java, and there have been many doubts as I have been reading from various sources. I have collected my concepts, and I would request to go through all of the points and comment on them. I came to know that memory allocation is JVM spec...
Simple state machine example in C#?
...is simple state diagram:
We have:
4 states (Inactive, Active, Paused, and Exited)
5 types of state transitions (Begin Command, End Command, Pause Command, Resume Command, Exit Command).
You can convert this to C# in a handful of ways, such as performing a switch statement on the current state...
How to sum a variable by group
...umns. First column contains categories such as "First", "Second", "Third", and the second column has numbers that represent the number of times I saw the specific groups from "Category".
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How is a tag different from a branch in Git? Which should I use, here?
I am having some difficulty understanding how to use tags versus branches in git .
12 Answers
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When would I use XML instead of SQL? [closed]
I've been working on database-driven web applications for a few years now and recently took on a project involving a CMS that is XML-capable. This has led me to think about the usage of XML/XSLT in general and in what situations it would be more useful than the approach I've always used, which is st...
What is the difference between & vs @ and = in angularJS
...ybody explain me the difference among these AngularJS operators: &, @ and = when isolating scope with proper example.
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