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@Basic(optional = false) vs @Column(nullable = false) in JPA
What's the difference between @Basic(optional = false) and @Column(nullable = false) in JPA persistence?
2 Answers
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curl -GET and -X GET
Curl offers a series of different http method calls that are prefixed with a X, but also offers the same methods without. I've tried both and I can't seem to figure out the difference. Can someone explain to me quickly how these two operations differ?
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querySelector, wildcard element match?
Is there a way to do a wildcard element name match using querySelector or querySelectorAll ? I see support for wildcards in attribute queries but not for the elements themselves.
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ERROR: permission denied for sequence cities_id_seq using Postgres
...t postgres (and at database info systems all in all). I ran following sql script on my database:
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Multiple columns index when using the declarative ORM extension of sqlalchemy
According to the documentation and the comments in the sqlalchemy.Column class, we should use the class sqlalchemy.schema.Index to specify an index that contains multiple columns.
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HTTP 401 - what's an appropriate WWW-Authenticate header value?
The application I'm working on at the moment has a session timeout value. If the user hasn't interacted for longer than this value, the next page they try to load, they will be prompted to log in.
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String.IsNullOrWhiteSpace in LINQ Expression
I have the following code:
5 Answers
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Assign pandas dataframe column dtypes
I want to set the dtype s of multiple columns in pd.Dataframe (I have a file that I've had to manually parse into a list of lists, as the file was not amenable for pd.read_csv )
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Is pass-by-value a reasonable default in C++11?
In traditional C++, passing by value into functions and methods is slow for large objects, and is generally frowned upon. Instead, C++ programmers tend to pass references around, which is faster, but which introduces all sorts of complicated questions around ownership and especially around memory ma...
How to check if std::map contains a key without doing insert?
The only way I have found to check for duplicates is by inserting and checking the std::pair.second for false , but the problem is that this still inserts something if the key is unused, whereas what I want is a map.contains(key); function.
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