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Ruby on Rails: How can I revert a migration with rake db:migrate?
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Run the following command
rake db:migrate:down VERSION=<version>
where <version> is the version number of your migration file you want to revert.
eg. if you want to revert a migration with file name 3846656238_create_users.rb
r...
Convert data.frame column format from character to factor
... of the variables (all numeric)
#one approach it to index with the $ sign and the as.factor function
mtcars$am <- as.factor(mtcars$am)
#another approach
mtcars[, 'cyl'] <- as.factor(mtcars[, 'cyl'])
str(mtcars) # now look at the classes
This also works for character, dates, integers and ot...
Partial classes in separate dlls
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From MSDN -Partial Classes and Methods:
All partial-type definitions meant to
be parts of the same type must be
defined in the same assembly and the
same module (.exe or .dll file).
Partial definitions cannot span
multiple modules.
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Fragment MyFragment not attached to Activity
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developer.android.com/reference/android/app/… ...there's also isDetached(), that was added on API level 13
– Lucas Jota
Mar 21 '14 at 12:42
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Cannot set property 'innerHTML' of null
... Cannot set property 'innerHTML' of null?
I thought I understood innerHTML and had it working before.
19 Answers
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How do I delete a fixed number of rows with sorting in PostgreSQL?
...'t change ctids, I don't think. Since that just compacts within each page, and the ctid is just the line number not a page offset. A VACUUM FULL or a CLUSTER operation would change the ctid, but those operations take an access exclusive lock on the table first.
– araqnid
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Mock HttpContext.Current in Test Init Method
...xt itself is fakeable just enough for you do replace the IPrincipal (User) and IIdentity.
The following code runs as expected, even in a console application:
HttpContext.Current = new HttpContext(
new HttpRequest("", "http://tempuri.org", ""),
new HttpResponse(new StringWriter())
);
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Select columns from result set of stored procedure
I have a stored procedure that returns 80 columns, and 300 rows. I want to write a select that gets 2 of those columns. Something like
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Command to remove all npm modules globally?
Is there a command to remove all global npm modules? If not, what do you suggest?
24 Answers
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What is the effect of encoding an image in base64?
...tring its becoming 500kb.Its not 37%.I have compressed a 5mb image to 70kb and then convert that compressed image to string that become 500kb.
– KJEjava48
Apr 19 '17 at 6:05
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