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One class per file rule in .NET? [closed]
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One class per file also gives you a better idea of what each check in is changing without looking at the diffs of the file.
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How can I make a JPA OneToOne relation lazy
...view was particularly slow. I profiled the view and noticed that there was one query executed by hibernate which took 10 seconds even if there only were two object in the database to fetch. All OneToMany and ManyToMany relations were lazy so that wasn't the problem. When inspecting the actual SQ...
JOIN queries vs multiple queries
...r more tables on different keys, often databases (i.e. mysql) can only use one index per table, meaning maybe one of the joins will be fast (and use an index) whereas the others will be extremely slow. For multiple queries, you can optimize the indexes to use for each query.
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How to express a One-To-Many relationship in Django
...'m defining my Django models right now and I realized that there wasn't a OneToManyField in the model field types. I'm sure there's a way to do this, so I'm not sure what I'm missing. I essentially have something like this:
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How to select rows from a DataFrame based on column values?
...({'A': 'foo bar foo bar foo bar foo foo'.split(),
'B': 'one one two three two two one three'.split(),
'C': np.arange(8), 'D': np.arange(8) * 2})
print(df)
# A B C D
# 0 foo one 0 0
# 1 bar one 1 2
# 2 foo two 2 4
# 3 bar three...
How to sort two lists (which reference each other) in the exact same way
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One classic approach to this problem is to use the "decorate, sort, undecorate" idiom, which is especially simple using python's built-in zip function:
>>> list1 = [3,2,4,1, 1]
>>> list2 = ['three', 'two', ...
Entity Framework: One Database, Multiple DbContexts. Is this a bad idea? [closed]
...t is meant to represent your database, and thus, if your application uses one database, you'd want only one DbContext .
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~x + ~y == ~(x + y) is always false?
...all x and y (mod 2n).
*It is interesting to note that on a machine with one's complement arithmetic, the equality actually holds true for all x and y. This is because under one's complement, ~x = -x. Thus, ~x + ~y == -x + -y == -(x+y) == ~(x+y).
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How can I verify if one list is a subset of another?
...a set (so much so that before we had sets in Python we used dictionaries). One wonders how the issue got less specific in three hours.
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Standard alternative to GCC's ##__VA_ARGS__ trick?
...eceived no response whatsoever from the committee; I don't even know if anyone read it. In 2016 it was proposed again in N2023, and I encourage anyone who knows how that proposal is going to let us know in the comments.
sha...