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How do you write a migration to rename an ActiveRecord model and its table in Rails?
...ble_name
end
end
I had to go and rename the model declaration file manually.
Edit:
In Rails 3.1 & 4, ActiveRecord::Migration::CommandRecorder knows how to reverse rename_table migrations, so you can do this:
class RenameOldTableToNewTable < ActiveRecord::Migration
def change
rena...
How to split a string literal across multiple lines in C / Objective-C?
...
There are two ways to split strings over multiple lines:
Using \
All lines in C can be split into multiple lines using \.
Plain C:
char *my_string = "Line 1 \
Line 2";
Objective-C:
NSString *my_string = @"Line1 \
Line2";
Better approach
Th...
Does reading an entire file leave the file handle open?
...hat on the particular Python implementation.
To understand what this is all about, pay particular attention to the actual file object. In your code, that object is mentioned only once, in an expression, and becomes inaccessible immediately after the read() call returns.
This means that the file...
How to find server name of SQL Server Management Studio
...13Khaneddy2013
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mysql :: insert into table, data from another table?
...000/svg\"\u003e\u003cpath d=\"M46.1709 9.17788C46.1709 8.26454 46.2665 7.94324 47.1084 7.58816C47.4091 7.46349 47.7169 7.36433 48.0099 7.26993C48.9099 6.97997 49.672 6.73443 49.672 5.93063C49.672 5.22043 48.9832 4.61182 48.1414 4.61182C47.4335 4.61182 46.7256 4.91628 46.0943 5.50789C45.7307 4.9328 4...
How to wait for several Futures?
...ave several futures and need to wait until either any of them fails or all of them succeed.
8 Answers
...
How to loop over files in directory and change path and add suffix to filename
...le of notes first: when you use Data/data1.txt as an argument, should it really be /Data/data1.txt (with a leading slash)? Also, should the outer loop scan only for .txt files, or all files in /Data? Here's an answer, assuming /Data/data1.txt and .txt files only:
#!/bin/bash
for filename in /Data/*...
Cleaner way to do a null check in C#? [duplicate]
...
Is this really considered cleaner?
– ClassicThunder
Jul 16 '13 at 13:35
23
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Modifying location.hash without page scrolling
...reated and placed at the current location of the scroll. It's the same visually as position:fixed/top:0. Thus the scrollbar is "moved" to the exact same spot it currently is on.
– Borgar
Sep 29 '09 at 0:44
...
Is there a performance difference between a for loop and a for-each loop?
... iterator or index variable
completely. The resulting idiom
applies equally to collections and
arrays:
// The preferred idiom for iterating over collections and arrays
for (Element e : elements) {
doSomething(e);
}
When you see the colon (:), read it as
“in.” Thus, the loop ab...