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How do you write a migration to rename an ActiveRecord model and its table in Rails?
...tion::CommandRecorder knows how to reverse rename_table migrations, so you can do this:
class RenameOldTableToNewTable < ActiveRecord::Migration
def change
rename_table :old_table_name, :new_table_name
end
end
(You still have to go through and manually rename your files.)
...
Are class names in CSS selectors case sensitive?
I keep reading everywhere that CSS is not case sensitive, but I have this selector
4 Answers
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When to add what indexes in a table in Rails
...add "index" to all the foreign keys like "xxx_id"?
It would be better, because it accelerates the search in sorting in this column. And Foreign keys are something searched for a lot.
Since Version 5 of rails the index will be created automatically, for more information see here.
Should I add ...
Difference between CC, gcc and g++?
... is different from what happens on Solaris, for example.
The easy part (because it is not platform-specific) is the separation of 'gcc' and 'g++':
gcc is the GNU C Compiler from the GCC (GNU Compiler Collection).
g++ is the GNU C++ Compiler from the GCC.
The hard part, because it is platform-sp...
Is GridFS fast and reliable enough for production?
... a new website and I want to use GridFS as storage for all user uploads, because it offers a lot of advantages compared to a normal filesystem storage.
...
How does git compute file hashes?
...
You can also compare this to the output of echo 'Hello, World!' | git hash-object --stdin. Optionally you can specify --no-filters to make sure no crlf conversion happens, or specify --path=somethi.ng to let git use the filter sp...
Configuring Log4j Loggers Programmatically
...
You can add/remove Appender programmatically to Log4j:
ConsoleAppender console = new ConsoleAppender(); //create appender
//configure the appender
String PATTERN = "%d [%p|%c|%C{1}] %m%n";
console.setLayout(new PatternLa...
Is a Python list guaranteed to have its elements stay in the order they are inserted in?
...
what if I return a local list from a function and use that in the calling function. That is def fn_1(): lst = [] lst.append(1) lst.append(2) return lst and def fn_2(): print(fn_1()) Will the order be same ALWAYS irrespective of how many times or ...
Is it safe to remove selected keys from map within a range loop?
How can one remove selected keys from a map?
Is it safe to combine delete() with range, as in the code below?
4 Answers
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SVN how to resolve new tree conflicts when file is added on two branches
...sting versioned file.
This should be a tree conflict on the file of the 'local obstruction, incoming add upon merge' variety. Fixed expectations in r35341.
(This is also called "evil twins" in ClearCase by the way):
a file is created twice (here "added" twice) in two different branches, creating tw...