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Set value to NULL in MySQL
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You're probably quoting 'NULL'. NULL is a reserved word in MySQL, and can be inserted/updated without quotes:
INSERT INTO user (name, something_optional) VALUES ("Joe", NULL);
UPDATE user SET something_optional = NULL;
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How do I view the list of functions a Linux shared library is exporting?
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What you need is nm and its -D option:
$ nm -D /usr/lib/libopenal.so.1
.
.
.
00012ea0 T alcSetThreadContext
000140f0 T alcSuspendContext
U atanf
U calloc
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.
.
Exported sumbols are indicated by a T. Required symbols that mus...
Custom Drawable for ProgressBar/ProgressDialog
...tes.xml declares the colors of the different states:
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item android:id="@android:id/background">
<shape>
<gradient
android:startColor="#000001"
...
Perform debounce in React.js
...is some initial wiring but you are composing primitive blocks on your own, and you can make your own custom hook so that you only need to do this once.
// Generic reusable hook
const useDebouncedSearch = (searchFunction) => {
// Handle the input text state
const [inputText, setInputText] = ...
How can I change UIButton title color?
... ViewController, The following instance method to change UIFont, tintColor and TextColor of the UIButton
Objective-C
buttonName.titleLabel.font = [UIFont fontWithName:@"LuzSans-Book" size:15];
buttonName.tintColor = [UIColor purpleColor];
[buttonName setTitleColor:[UIColor purpleColor] forSta...
How can a Javascript object refer to values in itself? [duplicate]
... In ES6 you can replace key2 : function() {...} with get key2() {...} and then you don't need to use brackets when calling it: alert(obj.key2);
– user993683
Dec 6 '16 at 5:54
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How to exit a function in bash
...pecified by N. If N is omitted, the return status is that of the
last command executed within the function or script.
Exit Status:
Returns N, or failure if the shell is not executing a function or script.
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Memoization in Haskell?
...f :: Int -> Int
faster_f n = f_list !! n
That performs passably well, and replaces what was going to take O(n^3) time with something that memoizes the intermediate results.
But it still takes linear time just to index to find the memoized answer for mf. This means that results like:
*Main Dat...
How can I match a string with a regex in Bash?
...is not a concern, I recommend using [[ instead of [ or test as it is safer and more powerful. See What is the difference between test, [ and [[ ? for details.
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How to Query an NTP Server using C#?
... ntpData = new byte[48];
//Setting the Leap Indicator, Version Number and Mode values
ntpData[0] = 0x1B; //LI = 0 (no warning), VN = 3 (IPv4 only), Mode = 3 (Client Mode)
var addresses = Dns.GetHostEntry(ntpServer).AddressList;
//The UDP port number assigned to NTP is 123
var ...