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Template default arguments
...template arguments must be present but you can leave them empty.
Think of it like a function foo with a single default argument. The expression foo won't call it, but foo() will. The argument syntax must still be there. This is consistent with that.
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Retrieving the last record in each group - MySQL
...upports windowing functions, like almost all popular SQL implementations. With this standard syntax, we can write greatest-n-per-group queries:
WITH ranked_messages AS (
SELECT m.*, ROW_NUMBER() OVER (PARTITION BY name ORDER BY id DESC) AS rn
FROM messages AS m
)
SELECT * FROM ranked_messages W...
What is the difference between IEnumerator and IEnumerable? [duplicate]
...ess to a collection. A collection that implements IEnumerable can be used with a foreach statement.
Definition
IEnumerable
public IEnumerator GetEnumerator();
IEnumerator
public object Current;
public void Reset();
public bool MoveNext();
example code from codebetter.com
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What is the optimal length for an email address in a database?
...ocal part that comes before the '@' sign, and the domain part that follows it. In "user@example.com", the local part is "user", and the domain part is "example.com".
The local part must not exceed 64 characters and the domain part cannot be longer than 255 characters.
The combined length of the lo...
How to serialize an object into a string
I am able to serialize an object into a file and then restore it again as is shown in the next code snippet. I would like to serialize the object into a string and store into a database instead. Can anyone help me?
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Which types can be used for Java annotation members?
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It's specified by section 9.6.1 of the JLS. The annotation member types must be one of:
primitive
String
an Enum
another Annotation
Class
an array of any of the above
It does seem restrictive, but no doubt there are reasons...
How to get the command line args passed to a running process on unix/linux systems?
...follow
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edited May 21 '19 at 14:49
jpaugh
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How to resolve git's “not something we can merge” error
I just encountered a problem when merging a branch into master in git. First, I got the branch name by running git ls-remote . Let's call that branch "branch-name". I then ran git merge branch-name command and got the following result:
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Django - how to create a file and save it to a model's FileField?
Here's my model. What I want to do is generate a new file and overwrite the existing one whenever a model instance is saved:
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C# Test if user has write access to a folder
I need to test if a user can write to a folder before actually attempting to do so.
18 Answers
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