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How do I modify a MySQL column to allow NULL?
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You want the following:
ALTER TABLE mytable MODIFY mycolumn VARCHAR(255);
Columns are nullable by default. As long as the column is not declared UNIQUE or NOT NULL, there shouldn't be any problems.
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Call a global variable inside module
...e called Projects.ts that I want to reference a global variable declared in a bootstrap plugin called bootbox.js .
6 Ans...
Display image as grayscale using matplotlib
I'm trying to display a grayscale image using matplotlib.pyplot.imshow() . My problem is that the grayscale image is displayed as a colormap. I need the grayscale because I want to draw on top of the image with color.
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Notification when a file changes?
Is there some mechanism by which I can be notified (in C#) when a file is modified on the disc?
3 Answers
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WPF TemplateBinding vs RelativeSource TemplatedParent
What is the difference between these 2 bindings:
6 Answers
6
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Are “elseif” and “else if” completely synonymous?
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From the PHP manual:
In PHP, you can also write 'else if' (in two words) and the behavior would be identical to the one of 'elseif' (in a single word). The syntactic meaning is slightly different (if you're familiar with C, this is the same behav...
postgresql - add boolean column to table set default
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ADD COLUMN "priv_user" BOOLEAN NOT NULL DEFAULT FALSE;
UPDATE: following is only true for versions before postgresql 11.
As Craig mentioned on filled tables it is more efficient to split it into steps:
ALTER TABLE users ADD COLUMN priv_user BOOLEAN;
UPDATE users SET priv_user = 'f';
ALTER TA...
java: (String[])List.toArray() gives ClassCastException
The following code (run in android) always gives me a ClassCastException in the 3rd line:
4 Answers
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How to append the output to a file?
How can I do something like command > file in a way that it appends to the file, instead of overwriting?
3 Answers
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e.printStackTrace equivalent in python
I know that print(e) (where e is an Exception) prints the occurred exception
but, I was trying to find the python equivalent of Java's e.printStackTrace() that exactly traces the exception to what line it occurred and prints the entire trace of it.
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