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When and why JPA entities should implement Serializable interface?
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This usually happens if you mix HQL and native SQL queries. In HQL, Hibernate maps the types you pass in to whatever the DB understands. When you run native SQL, then you must do the mapping yourself. If you don't, then the default m...
Showing line numbers in IPython/Jupyter Notebooks
...l line numbers. In more recent notebook versions Shift-L should toggle for all cells.
If you can't remember the shortcut, bring up the command palette Ctrl-Shift+P (Cmd+Shift+P on Mac), and search for "line numbers"), it should allow to toggle and show you the shortcut.
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What is the difference between a 'closure' and a 'lambda'?
... function definition is re-written as binding a lambda to a variable internally. In other languages, like Python, there are some (rather needless) distinctions between them, but they behave the same way otherwise.
A closure is any function which closes over the environment in which it was defined. ...
How to assign colors to categorical variables in ggplot2 that have stable mapping?
...maintain consistent color schemes across multiple data frames that are not all obtained by subsetting a single large data frame. Managing the factors levels in multiple data frames can become tedious if they are being pulled from separate files and not all factor levels appear in each file.
One way...
How to start new activity on button click
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Yeah, easy lol. There is more codemissing than code actually typed. Where is all xml interface and .java code missing? Downvote
– Liquid Core
Jun 21 '15 at 12:50
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Static variable inside of a function in C
...o() to the return from foo(); so it would be re-initialized to 5 on every call.
The keyword static acts to extend the lifetime of a variable to the lifetime of the programme; e.g. initialization occurs once and once only and then the variable retains its value - whatever it has come to be - over al...
How to find the size of localStorage
...ly developing a site that will make use of HTML5's localStorage. I've read all about the size limitations for different browsers. However, I haven't seen anything on how to find out the current size of a localStorage instance. This question seems to indicate that JavaScript doesn't have a built in...
What's the result of += in C and C++?
...7.1:
The assignment operator (=) and the compound assignment operators all group right-to-left. All require a modifiable
lvalue as their left operand and return an lvalue with the type and value of the left operand after the assignment has taken place.
EDIT : The behavior of (i+=10)+=10 in ...
How do you remove an invalid remote branch reference from Git?
...might be needing a prune:
git remote prune public
prune
Deletes all stale tracking branches under <name>. These stale branches have already been removed from the remote repository referenced by <name>, but are still locally available in "remotes/<name>".
With --dry-...
Studies on optimal code width?
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Actually, the 80-column thing long precedes DOS. It comes from card punches, which were 80-column devices.
And to kind of answer the OP's question, one "study" has been going on for about 600 years now - the printed book. These ...