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JPA EntityManager: Why use persist() over merge()?
EntityManager.merge() can insert new objects and update existing ones.
15 Answers
15
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dynamic_cast and static_cast in C++
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Here's a rundown on static_cast<> and dynamic_cast<> specifically as they pertain to pointers. This is just a 101-level rundown, it does not cover all the intricacies.
static_cast< Type* >(ptr)
This takes the pointer in ptr and tries to safely ...
Use tnsnames.ora in Oracle SQL Developer
...-> Preferences, as shown in below image.
In the Preferences options expand Database --> select Advanced --> under "Tnsnames Directory" --> Browse the directory where tnsnames.ora present.
Then click on Ok,
as shown in below diagram.
tnsnames.ora available at Drive:\oracle\product\10x.x....
Fast way of finding lines in one file that are not in another?
...ile1 file2
The input files should be sorted for this to work. With bash (and zsh) you can sort in-place with process substitution <( ):
diff --new-line-format="" --unchanged-line-format="" <(sort file1) <(sort file2)
In the above new and unchanged lines are suppressed, so only changed...
Getting the caller function name inside another function in Python? [duplicate]
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There are two ways, using sys and inspect modules:
sys._getframe(1).f_code.co_name
inspect.stack()[1][3]
The stack() form is less readable and is implementation dependent since it calls sys._getframe(), see extract from inspect.py:
def stack(context=...
Remove specific commit
I was working with a friend on a project, and he edited a bunch of files that shouldn't have been edited. Somehow I merged his work into mine, either when I pulled it, or when I tried to just pick the specific files out that I wanted. I've been looking and playing for a long time, trying to figure o...
How to make tinymce paste in plain text by default
Googled it thousands of times, No one gives a complete solution of how to make Tinymce paste in plain text by default and strip out any formatting without clicking the "paste as text" button.
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What is null in Java?
...ceof operator is true if the value of the RelationalExpression is not null and the reference could be cast to the ReferenceType without raising a ClassCastException. Otherwise the result is false.
This means that for any type E and R, for any E o, where o == null, o instanceof R is always false.
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A better similarity ranking algorithm for variable length strings
....com/articles/StrikeAMatch.html
Simon has a Java version of the algorithm and below I wrote a PL/Ruby version of it (taken from the plain ruby version done in the related forum entry comment by Mark Wong-VanHaren) so that I can use it in my PostgreSQL queries:
CREATE FUNCTION string_similarity(str...
What's the difference between an argument and a parameter?
...ng else. Either way the other people know what I mean, but what's correct, and what's the history of the terms?
34 Answers
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