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IntelliJ IDEA way of editing multiple lines
...ossibility to edit multiple lines.
Use:
Alt + Shift + Mouse click
for selection. More about this new improvement in IntelliJ blogpost here. Very useful feature.
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Is there a way to change the environment variables of another process in Unix?
...ocesses.
Suppose that you write your own shared library which implements 'char *getenv'. Then, you set up 'LD_PRELOAD' or 'LD_LIBRARY_PATH' env. vars so that both your processes are run with your shared library preloaded.
This way, you will essentially have a control over the code of the 'getenv' ...
Convert to absolute value in Objective-C
...+ programs too.)
(Alas, there is no habs(short) function. Or scabs(signed char) for that matter...)
Apple's and GNU's Objective-C headers also include an ABS() macro which is type-agnostic. I don't recommend using ABS() however as it is not guaranteed to be side-effect-safe. For instance, ABS(a+...
Insert all values of a table into another table in SQL
.... But the insert statement accepts values, but i would like it to accept a select * from the initial_Table. Is this possible?
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How can prepared statements protect from SQL injection attacks?
...ample shows it (all examples in PHP/Mysql):
$expected_data = 1;
$query = "SELECT * FROM users where id=$expected_data";
will produce a regular query
SELECT * FROM users where id=1
while this code
$spoiled_data = "1; DROP TABLE users;"
$query = "SELECT * FROM users where id=$spoiled_da...
Linq: What is the difference between Select and Where
The Select and Where methods are available in Linq. What should every developer know about these two methods? For example: when to use one over the other, any advantages of using one over the other, etc.
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Expert R users, what's in your .Rprofile? [closed]
...se it might breaks my coauthors' code, I wish it was the default. Why?
1) Character vectors use less memory (but only barely);
2) More importantly, we would avoid problems such as:
> x <- factor(c("a","b","c"))
> x
[1] a b c
Levels: a b c
> x <- c(x, "d")
> x
[1] "1" "2" "3" "...
Why are Where and Select outperforming just Select?
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Select iterates once over the entire set and, for each item, performs a conditional branch (checking for validity) and a + operation.
Where+Select creates an iterator that skips invalid elements (doesn't yield them), perform...
Insert the carriage return character in vim
...tored a file in Unix ( \n newlines). I need to insert the carriage return character ( U+000D aka \r ). When I try to paste it from the clipboard ( "+p ) or type it using Ctrl + Shift + u - 000d , the linefeed is inserted ( U+000A ).
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Count number of records returned by group by
...
You can do both in one query using the OVER clause on another COUNT
select
count(*) RecordsPerGroup,
COUNT(*) OVER () AS TotalRecords
from temptable
group by column_1, column_2, column_3, column_4
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