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Chaining multiple filter() in Django, is this a bug?
...
As you can see in the generated SQL statements the difference is not the "OR" as some may suspect. It is how the WHERE and JOIN is placed.
Example1 (same joined table) :
(example from https://docs.djangoproject.com/en/dev/topics/db/queries/#spanning-mult...
Good example of livelock?
...ple is two competing processes live locking in an attempt to correct for a SQL server deadlock, with each process using the same wait-retry algorithm for retrying. While it's the luck of timing, I have seen this happen on separate machines with similar performance characteristics in response to a me...
Advantage of creating a generic repository vs. specific repository for each object?
...aces, but a base class for the implementations. For example, using LINQ to SQL, you could do:
public abstract class Repository<TEntity>
{
private DataContext _dataContext;
protected Repository(DataContext dataContext)
{
_dataContext = dataContext;
}
protected IQu...
Django: “projects” vs “apps”
...en contains a few other things, including but not limited to wsgi scripts, sql scripts etc.
django's management extensions rely on subdirectories. So it makes sense to name packages appropriately.
In short, the reason there is a convention is the same as any other convention - it helps when it com...
MySQL: @variable vs. variable. What's the difference?
...
MySQL has a concept of user-defined variables.
They are loosely typed variables that may be initialized somewhere in a session and keep their value until the session ends.
They are prepended with an @ sign, like this: @var
You ...
MVC Razor view nested foreach's model
...w it does its work is important here.
(Note other frameworks like LINQ to SQL do similar things by walking an expression tree and building a different grammar, that this case a SQL query)
How does the Model Binder work?
So once you get that, we have to briefly talk about the model binder. When th...
How to append rows to an R data frame
...operation and couple it with manually doubling the table when needed.
Use RSQLite and append to the table held in memory.
data.frame's own ability to grow and use custom environment (which has reference semantics) to store the data.frame so it will not be copied on return.
Here is a test of all th...
What is the proper way to re-attach detached objects in Hibernate?
...alse(book == _book);
});
And Hibernate is going to execute the following SQL statements:
SELECT
b.id,
b.author AS author2_0_,
b.isbn AS isbn3_0_,
b.title AS title4_0_
FROM
book b
WHERE
b.id = 1
-- Merging the Book entity
UPDATE
book
SET
author = 'Vlad Mihalcea',
...
Local Storage vs Cookies
...small in size, cookies are sent with every HTTP request Limited size
(4KB)
SQL injection can be performed from a cookie
Local storage
Pros
Support by most modern browsers
Persistent data that is stored directly in the browser
Same-origin rules apply to local storage data
Is not sent with every...
How serious is this new ASP.NET security vulnerability and how can I workaround it?
...information in a database connection string, or even link to an automouted sql-express database which you don't want someone to get hold of. But if you are following best practice you use Protected Configuration to encrypt all sensitive data in your web.config.
Links to references
Read Microsoft's...