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Change a column type from Date to DateTime during ROR migration
... This answer is only partially correct, you can not use change_column inside change even on rails 4 or down migration will not work. You should use up/down no matter the version of rails.
– Alan Peabody
Jul 18 '14 at 18:31
...
How should I escape commas and speech marks in CSV files so they work in Excel?
...new strings by replacing text in old one's as they have their own share inside heap memory. If you want, you can unconditionally replace all values and tell us if it causes any issue although it shouldn't.
– AlphaBetaGamma
Jan 13 '15 at 6:33
...
Avoid line break between html elements
...ted and inserted by JavaScript) you also may want to try to insert a zero width joiner:
.wrapper{
width: 290px;
white-space: no-wrap;
resize:both;
overflow:auto;
border: 1px solid gray;
}
.breakable-text{
display: inline;
white-space: no-wrap;
}
.no-break-before...
Add up a column of numbers at the Unix shell
..."import sys; print(sum(int(x) for x in sys.stdin))" Traceback (most recent call last): File "<string>", line 1, in <module> File "<string>", line 1, in <genexpr> ValueError: invalid literal for int() with base 10: '\n'
– don bright
J...
Joining two lists together
...d. AddRange edits a list in place, adding the second list to it (as if you called .Add(foo) a bunch of times). The Concat and Union extension methods don't change the original list. They lazily construct a new IEnumerable and won't even access the original list members unless necessary. As noted, Un...
What is HTML5 ARIA?
...utes on HTML5 elements), which can be used by the web app developer to provide additional information about the semantics of the various elements to assistive technologies like screen readers. Of course, for ARIA to work, the HTTP user agent that interprets the markup needs to support ARIA, but the ...
How to generate an openSSL key using a passphrase from the command line?
...er when run from a script the command will not ask for a password so to avoid the password being viewable as a process use a function in a shell script:
get_passwd() {
local passwd=
echo -ne "Enter passwd for private key: ? "; read -s passwd
openssl genpkey -aes-256-cbc -pass pass:$pass...
How to completely remove borders from HTML table
..."priority" calculated and what border styles are "stronger" (double vs. solid etc.).
I did like this:
<table cellspacing="0" cellpadding="0">
<tr>
<td class="first">first row</td>
</tr>
<tr>
<td class="second">second row</td>
</tr...
What does the `#` operator mean in Scala?
...
To explain it, we first have to explain nested classes in Scala. Consider this simple example:
class A {
class B
def f(b: B) = println("Got my B!")
}
Now let's try something with it:
scala> val a1 = new A
a1: A = A@2fa8ecf4
scala> val a2 = new A
a2: A = A@4bed4c8
scala> a2....
What does the “@” symbol do in Powershell?
...to check out Jeffrey Snover's answer below... @ is more than just an array identifier.
– Eric Schoonover
Sep 15 '09 at 6:47
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