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MySQL show current connection info
...ER();
This will return something like root@localhost so you get the host and the user.
To get the current database run this statement:
SELECT DATABASE();
Other useful functions can be found here: http://dev.mysql.com/doc/refman/5.0/en/information-functions.html
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How can two strings be concatenated?
...osters pointed out, paste can do two things:
concatenate values into one "string", e.g.
> paste("Hello", "world", sep=" ")
[1] "Hello world"
where the argument sep specifies the character(s) to be used between the arguments to concatenate,
or collapse character vectors
> x <- c("Hello"...
What's the difference between SoftReference and WeakReference in Java?
...ort java.util.HashMap;
public class Test {
public static void main(String args[]) {
HashMap<Employee, EmployeeVal> aMap = new
HashMap<Employee, EmployeeVal>();
Employee emp = new Employee("Vinoth");
EmployeeVal val = new EmployeeVa...
Red black tree over avl tree
...ack tree.
AVL trees store the balance factor at each node. This takes O(N) extra space. However, if we know that the keys that will be inserted in the tree will always be greater than zero, we can use the sign bit of the keys to store the colour information of a red-black tree. Thus, in such cases r...
Map implementation with duplicate keys
...ions external library. You can simply implement the following Map:
Map<String, ArrayList<String>> hashMap = new HashMap<String, ArrayList>();
public static void main(String... arg) {
// Add data with duplicate keys
addValues("A", "a1");
addValues("A", "a2");
addValues...
Django REST Framework: adding additional field to ModelSerializer
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So, based on this answer, if you want to pass say 12 extra fields to your serializer, you need to define 12 specific methods for each field that just returns foo.field_custom ?
– AlxVallejo
Apr 13 '18 at 19:13
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Why would $_FILES be empty when uploading files to PHP?
...e WampServer 2 installed on my Windows 7 computer. I'm using Apache 2.2.11 and PHP 5.2.11. When I attempt to upload any file from a form, it seems to upload, but in PHP, the $_FILES array is empty. There is no file in the c:\wamp\tmp folder. I have configured php.ini to allow file uploads and ...
How to store arbitrary data for some HTML tags
...hat data in a div. Obviously in this example, I need each link to store an extra bit of information: the id of the article. The way I've been handling it in case was to put that information in the href link this:
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Emulate a do-while loop in Python?
...lso, is this real code where you are processing comments? What if you have strings with slashes? ie: print "blah // <-- does that mess you up?"
– Tom
Apr 13 '09 at 7:44
4
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Case insensitive 'in'
...pper() for name in USERNAMES) would create only a generator and one needed string at a time - massive memory savings if you're doing this operation a lot. (even more savings, if you simply create a list of lowercase usernames that you reuse for checking every time)
– viraptor
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