大约有 48,000 项符合查询结果（耗时：0.0575秒） [XML]
How to automatically install Emacs packages by specifying a list of package names?
...a list of package names in .emacs file and then package could automatically search and install the packages, so that I don't need to install them manually by calling M-x package-list-packages . How to do that?
...
How to create a project from existing source in Eclipse and then find it?
I have created several .java files. All of them are located in one directory. I used a text editor to write these files. Now I want to switch to Eclipse. How can I do it? I have tried many ways. None of them works.
...
Linking R and Julia?
...e.g. here ), but I suspect it will not be anywhere near R in terms of overall statistics workflow for some time yet. So I'd like to use it where C++ is mainly used in R programs: to optimize slow portions of code. Before I invest the time in learning Julia, though, I am curious what facilities th...
Show a popup/message box from a Windows batch file
...
I would make a very simple VBScript file and call it using CScript to parse the command line parameters.
Something like the following saved in MessageBox.vbs:
Set objArgs = WScript.Arguments
messageText = objArgs(0)
MsgBox messageText
Which you would call like:
cscr...
Is there a job scheduler library for node.js? [closed]
...'t this kind of library how this should be implemented? Should I just set callback to be called every second and check the time and start jobs scheduled for the time or what?
...
What happens if you don't commit a transaction to a database (say, SQL Server)?
...ou don't COMMIT or ROLLBACK a transaction, it's still "running" and potentially holding locks.
If your client (application or user) closes the connection to the database before committing, any still running transactions will be rolled back and terminated.
...
Avoiding instanceof in Java
...is entry from Steve Yegge's Amazon blog: "when polymorphism fails". Essentially he's addressing cases like this, when polymorphism causes more trouble than it solves.
The issue is that to use polymorphism you have to make the logic of "handle" part of each 'switching' class - i.e. Integer etc. in ...
What exception classes are in the standard C++ library
...;exception> interface (debatable if you should catch this)
std::bad_alloc <new> failure to allocate storage
std::bad_array_new_length <new> invalid array length
std::bad_cast <typeinfo> execution of an invalid dynamic-cast
std::bad_exception <exception>...
ORA-00979 not a group by expression
...
You must put all columns of the SELECT in the GROUP BY or use functions on them which compress the results to a single value (like MIN, MAX or SUM).
A simple example to understand why this happens: Imagine you have a database like this:
...
Get list from pandas DataFrame column headers
...input so I won't know how many columns there will be or what they will be called.
19 Answers
...