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What is the purpose of AsQueryable()?
...yable but that also has an instance Select method. If that were the case, and you wanted to use the LINQ Select method, you'd need to change the compile time type of the object to IQueryable. You could just cast it, but by having an AsQueryable method you can take advantage of type inference. Thi...
“git diff” does nothing
...figuration error somewhere, but I can't figure out where. Regular git commands appear to work fine, but "git diff" does nothing. To be safe, I removed external diff tools from my .gitconfig file. This was installed via MacPorts and is the lates version (1.7.2.2).
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Java SafeVarargs annotation, does a standard or best practice exist?
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1) There are many examples on the Internet and on StackOverflow about the particular issue with generics and varargs. Basically, it's when you have a variable number of arguments of a type-parameter type:
<T> void foo(T... args);
In Java, varargs are a syntac...
Cannot change column used in a foreign key constraint
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The type and definition of foreign key field and reference must be equal.
This means your foreign key disallows changing the type of your field.
One solution would be this:
LOCK TABLES
favorite_food WRITE,
person WRITE;
AL...
How to get a value from a cell of a dataframe?
...ith only one row, then access the first (only) row as a Series using iloc, and then the value using the column name:
In [3]: sub_df
Out[3]:
A B
2 -0.133653 -0.030854
In [4]: sub_df.iloc[0]
Out[4]:
A -0.133653
B -0.030854
Name: 2, dtype: float64
In [5]: sub_df.iloc[0]['A']
Ou...
DTO and DAO concepts and MVC [closed]
1) Why do we use DTO and DAO , and when should we use them. I am developing a GUI Java software to do with inserting, editing, deleting data. But I am struggling to distinguish between DTO/DAO and Model , View , Controller (MVC) Structure? Are they similar, which is better to use when i...
Write string to text file and ensure it always overwrites the existing content.
I have a string with a C# program that I want to write to a file and always overwrite the existing content. If the file isn't there, the program should create a new file instead of throwing an exception.
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Using HTML5/Canvas/JavaScript to take in-browser screenshots
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JavaScript can read the DOM and render a fairly accurate representation of that using canvas. I have been working on a script which converts HTML into a canvas image. Decided today to make an implementation of it into sending feedbacks like you describe...
Git branching: master vs. origin/master vs. remotes/origin/master
I think I'm on the right track to understand the basic concepts of git.
7 Answers
7
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Add a default value to a column through a migration
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I tried it on PostgreSQL and it updated previously created fields.
– Aboozar Rajabi
May 12 '16 at 6:31
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