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Add a default value to a column through a migration
..., since change_column is irreversible.
Instead, though it may be a couple extra lines, you should use def up and def down
So if you have a column with no default value, then you should do this to add a default value.
def up
change_column :users, :admin, :boolean, default: false
end
def down
...
How can I add a column that doesn't allow nulls in a Postgresql database?
...
Or, create a new table as temp with the extra column, copy the data to this new table while manipulating it as necessary to fill the non-nullable new column, and then swap the table via a two-step name change.
Yes, it is more complicated, but you may need to do it...
How to set up a PostgreSQL database in Django
...org/psycopg/, then install it under Python PATH
After downloading, easily extract the tarball and:
$ python setup.py install
Or if you wish, install it by either easy_install or pip.
(I prefer to use pip over easy_install for no reason.)
$ easy_install psycopg2
$ pip install psycopg2
Config...
How to make a smaller RatingBar?
...
you can remove some extra padding by specifying height of rating bar ex : android:layout_height="40dp"
– Manohar Reddy
Aug 28 '17 at 13:43
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How can I get the count of milliseconds since midnight for the current?
...) for Android specifically.
See How to use ThreeTenABP….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.
...
What does the leading semicolon in JavaScript libraries do?
...hat a third file contains this dirty fix. Why can not the concatenator add extra semicolons between files in the result?
– Dávid Horváth
Dec 3 '15 at 12:06
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The import android.support cannot be resolved
...4.jar file, usually the path for the Jar file is :
YOUR_DRIVE\android-sdks\extras\android\support\v4\android-support-v4.jar
After adding android-support-v4.jar Library, navigate to the Order and Export tab and put check mark on the android-support-v4 Library file.
After doing the above, Clean the P...
trying to align html button at the center of the my page [duplicate]
...ents, you'll have to provide wrapper elements for those. I don't think the extra div is worse than applying custom rules for navigation and other page elements that would otherwise be affected.
– Mohamad
Jul 9 '13 at 15:48
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Best data type for storing currency values in a MySQL database
...ecimal(19,4) both use 9 bytes of storage, so might as well spring for that extra 9 digits of scale.
– Adam Nofsinger
Mar 24 '10 at 14:50
1
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Super slow lag/delay on initial keyboard animation of UITextField
... @Vadoff Solution works, but have 2 minuses: 1) I have about 1 extra second of app loading; 2) Received memory warning (but, not all the time). I tried to add this code to UIViewController in viewDidLoad, but had no effect, maybe I made something wrong? Could you edit your answer and ad...