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How to change a nullable column to not nullable in a Rails migration?
I created a date column in a previous migration and set it to be nullable. Now I want to change it to be not nullable. How do I go about doing this assuming there are null rows in that database? I'm ok with setting those columns to Time.now if they're currently null.
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ANTLR: Is there a simple example?
...message, and the files ExpLexer.java, ExpParser.java and Exp.tokens should now be generated.
To see if it all works properly, create this test class:
import org.antlr.runtime.*;
public class ANTLRDemo {
public static void main(String[] args) throws Exception {
ANTLRStringStream in = n...
How to update Identity Column in SQL Server?
... it started
with a big number 10010 and it's related with another table, now I have 200 records and I want to fix this issue before the records increases.
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Can git automatically switch between spaces and tabs?
... .git/info/attributes which contains:
*.py filter=tabspace
Linux/Unix
Now run the commands:
git config --global filter.tabspace.smudge 'unexpand --tabs=4 --first-only'
git config --global filter.tabspace.clean 'expand --tabs=4 --initial'
OS X
First install coreutils with brew:
brew install...
Git - Undo pushed commits
...some commited changes already pushed to remote and pulled from the server. Now, I want to undo those changes. So I could just git checkout to the commit before the changes and commit the new changes, but I'm guessing that there will be problems to push them again to remote. Any suggestion on how s...
Update git commit author date when amending
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FTR, looks like on OS X, date doesn't know -R. Using date without options did the job anyway
– ksol
Feb 2 '12 at 10:29
7
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Ruby max integer
I need to be able to determine a systems maximum integer in Ruby. Anybody know how, or if it's possible?
6 Answers
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Get Output From the logging Module in IPython Notebook
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For anyone trying to do this in Python 3: reload is now imp.reload
– kuzzooroo
Jan 15 '15 at 17:09
11
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Calculate difference between two datetimes in MySQL
...rence between the last login time and the current time (which I get using NOW() ).
3 Answers
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In the shell, what does “ 2>&1 ” mean?
...file
Mon Jan 7 13:18:21 CET 2013
The file is overwritten each time, well now:
$ set -o noclobber
$ date > $testfile ; cat $testfile
bash: /tmp/testNoClobberDate-WW1xi9: cannot overwrite existing file
Mon Jan 7 13:18:21 CET 2013
$ date > $testfile ; cat $testfile
bash: /tmp/testNoClobberDa...