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How to create a MySQL hierarchical recursive query
... parent_id
from products
where parent_id = 19
union all
select p.id,
p.name,
p.parent_id
from products p
inner join cte
on p.parent_id = cte.id
)
select * from cte;
The value specified in parent_id = 19 should be set to the...
Encrypting & Decrypting a String in C# [duplicate]
...be getting a lot of upvotes, I've updated it to fix silly bugs and to generally improve the code based upon comments and feedback. See the end of the post for a list of specific improvements.
As other people have said, Cryptography is not simple so it's best to avoid "rolling your own" encryption ...
How do you mock out the file system in C# for unit testing?
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Edit: Install the NuGet package System.IO.Abstractions.
This package did not exist when this answer was originally accepted. The original answer is provided for historical context below:
You could do it by creating an interface:
inter...
How can I list all foreign keys referencing a given table in SQL Server?
...highly referenced table in a SQL Server database. How can I get a list of all the foreign key constraints I will need to remove in order to drop the table?
...
Running python script inside ipython
...
from within the directory of "my_script.py" you can simply do:
%run ./my_script.py
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How to avoid Dependency Injection constructor madness?
..., more coarse-grained interface that hides the interaction between some or all of the fine-grained dependencies you currently require.
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Performance surprise with “as” and nullable types
...lable types, and I'm adding a section about using the "as" operator, which allows you to write:
10 Answers
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Why use double indirection? or Why use pointers to pointers?
... word = malloc(4 * sizeof *word); // assume it worked
strcpy(word, "foo");
sentence = malloc(4 * sizeof *sentence); // assume it worked
sentence[0] = word;
sentence[1] = word;
sentence[2] = word;
sentence[3] = NULL;
monologue = malloc(4 * sizeof *monologue); // assum...
How do I create a file and write to it in Java?
...te that each of the code samples below may throw IOException. Try/catch/finally blocks have been omitted for brevity. See this tutorial for information about exception handling.
Note that each of the code samples below will overwrite the file if it already exists
Creating a text file:
PrintWriter...
List of Big-O for PHP functions
After using PHP for a while now, I've noticed that not all built-in PHP functions are as fast as expected. Consider these two possible implementations of a function that finds if a number is prime using a cached array of primes.
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