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Difference between Destroy and Delete
...cendants, not children: according to the documentation, destroy "creates a new object from the attributes, and then calls destroy on it." rubydoc.info/docs/rails/4.1.7/ActiveRecord%2FRelation:destroy
– Marco Lackovic
Jan 9 at 15:15
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retrieve links from web page using python and BeautifulSoup [closed]
...attribute are skipped.
BeautifulSoup 3 stopped development in March 2012; new projects really should use BeautifulSoup 4, always.
Note that you should leave decoding the HTML from bytes to BeautifulSoup. You can inform BeautifulSoup of the characterset found in the HTTP response headers to assist ...
rails - Devise - Handling - devise_error_messages
...this
# In application.html.erb
<% flash.each do |name, msg| %>
# New code (allow for flash elements to be arrays)
<% if msg.class == Array %>
<% msg.each do |message| %>
<%= content_tag :div, message, :id => "flash_#{name}" %>
<% end %>
<% el...
How to change column datatype in SQL database without losing data
... ALTER COLUMN YourColumnName BIT
The other option would be to create a new column of type BIT, fill it from the old column, and once you're done, drop the old column and rename the new one to the old name. That way, if something during the conversion goes wrong, you can always go back since you ...
Using a Single Row configuration table in SQL Server database. Bad idea?
...o each setting individually
negative: a schema change is required to add a new setting
negative: the table can become very wide if there are lots of settings
Key/Value Pair
positive: adding new settings does not require a schema change
positive: the table schema is narrow, with extra rows being us...
MemoryCache does not obey memory limits in configuration
...d of the MemoryCache does not get enough CPU time for cleaning, while many new elements are added.
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A variable modified inside a while loop is not remembered
...;
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}
Variable $lines can be converted to an array without starting a new sub-shell. The characters \ and n has to be converted to some character (e.g. a real new line character) and use the IFS (Internal Field Separator) variable to split the string into array elements. This can be done like:
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What's the difference between deadlock and livelock?
...ock;
public class DeadlockSample {
private static final Lock lock1 = new ReentrantLock(true);
private static final Lock lock2 = new ReentrantLock(true);
public static void main(String[] args) {
Thread threadA = new Thread(DeadlockSample::doA,"Thread A");
Thread threadB...
Random float number generation
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C++11 gives you a lot of new options with random. The canonical paper on this topic would be N3551, Random Number Generation in C++11
To see why using rand() can be problematic see the rand() Considered Harmful presentation material by Stephan T. La...
Single script to run in both Windows batch and Linux Bash?
...part
exit
:batch_part
echo %PATH%
Probably you'll need to use /r/n as a new line instead of a unix style.If I remember correct the unix new line is not interpreted as a new line by .bat scripts.Another way is to create an #.exe file in the path that does do nothing in similar manner as my answer ...