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How to add a primary key to a MySQL table?
... Column
If you want to add a primary key constraint to an existing column all of the previously listed syntax will fail.
To add a primary key constraint to an existing column use the form:
ALTER TABLE `goods`
MODIFY COLUMN `id` INT(10) UNSIGNED PRIMARY KEY AUTO_INCREMENT;
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How to print a date in a regular format?
...do with that?
Well, when you manipulate dates, keep using the date objects all long the way. They got thousand of useful methods and most of the Python API expect dates to be objects.
When you want to display them, just use str(). In Python, the good practice is to explicitly cast everything. So jus...
Algorithm to calculate the number of divisors of a given number
...ere's a Dr. Math that explains what exactly it is you need to do mathematically.
Essentially it boils down to if your number n is:
n = a^x * b^y * c^z
(where a, b, and c are n's prime divisors and x, y, and z are the number of times that divisor is repeated)
then the total count for all of the di...
What is eager loading?
...hing when asked. Classic example is when you multiply two matrices. You do all the calculations. That's eager loading;
Lazy loading: you only do a calculation when required. In the previous example, you don't do any calculations until you access an element of the result matrix; and
Over-eager loadin...
How to create EditText with rounded corners? [closed]
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Except that your solution uses the same drawable for all states. A regular EditText has different backgrounds for focused, disabled, pressed, and selected, besides the default. Focused, in particular, may be important going forward if we get some Android devices that lack touch...
Why does npm install say I have unmet dependencies?
I have a node package. When I run npm install from the package root, it installs a bunch of things, but then prints several error messages that look like this:
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RegEx to parse or validate Base64 data
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The simplest solution would be to strip out all whitespace (which is ignored as per the RFC) before validation.
– Ben Blank
Jan 24 '09 at 1:35
2
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Remove leading zeros from a number in Javascript [duplicate]
...console.log(`Subtracting zero conversion result: ${parsedNumber}`);
All results will be incorrect.
That's because, when converted, the numString value is greater than Number.MAX_SAFE_INTEGER. i.e.,
99999999999999999999 > 9007199254740991
This means all operation performed with the as...
Why does make think the target is up to date?
... not-file-related targets, you should make them phony as follows:
.PHONY: all test clean
Note that you can declare all of your phony targets there.
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Why is Node.js single threaded? [closed]
...rvers every client request is instantiated on a new thread. But in Node.js all the clients run on the same thread (they can even share the same variables!) I understand that I/O operations are event-based so they don't block the main thread loop.
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