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Best way to test if a row exists in a MySQL table
...OM test WHERE text LIKE '%something%'
LIMIT 1) : 0.044898986816406s.
But now, with a BIGINT PK field, only one entry is equal to '321321' :
SELECT * FROM test2 WHERE id ='321321' LIMIT 1 with
mysql_num_rows() : 0.0089840888977051s.
SELECT count(*) as count FROM test2 WHERE id ='321321' : 0.0003...
What is C# analog of C++ std::pair?
...
Tuple<> is now a better solution.
– dkantowitz
Aug 3 '12 at 7:06
6
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List of lists changes reflected across sublists unexpectedly
...than a matrix = [row] * 2 where both rows are exactly the same object, and now changes to one row matrix[0][0] = y suddenly reflect in the other one (matrix[0][0] is matrix[1][0]) == True
– nadrimajstor
Jul 2 '17 at 15:44
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How can building a heap be O(n) time complexity?
...t of the nodes we are calling siftDown from the bottom of the tree, we are now calling siftDown from the top of the tree on each iteration! Although the tree is shrinking, it doesn't shrink fast enough: The height of the tree stays constant until you have removed the first half of the nodes (when yo...
Difference between private, public, and protected inheritance
...like to describe member's accessors first in my own words. If you already know this, skip to the heading "next:".
There are three accessors that I'm aware of: public, protected and private.
Let:
class Base {
public:
int publicMember;
protected:
int protectedMember;
pr...
How to change collation of database, table, column?
The database is latin1_general_ci now and I want to change collation to utf8mb4_general_ci .
19 Answers
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What is a non-capturing group in regular expressions?
...tp://stackoverflow.com/
https://stackoverflow.com/questions/tagged/regex
Now, if I apply the regex below over it...
(https?|ftp)://([^/\r\n]+)(/[^\r\n]*)?
... I would get the following result:
Match "http://stackoverflow.com/"
Group 1: "http"
Group 2: "stackoverflow.com"
Group 3...
How to 'bulk update' with Django?
...
Update:
Django 2.2 version now has a bulk_update.
Old answer:
Refer to the following django documentation section
Updating multiple objects at once
In short you should be able to use:
ModelClass.objects.filter(name='bar').update(name="foo")
...
Why do you have to call .items() when iterating over a dictionary in Python?
...hen would you ever write a condition like this?
if (key, value) in dict:
Now it's not necessary that the in operator and for ... in operate over the same items. Implementation-wise they are different operations (__contains__ vs. __iter__). But that little inconsistency would be somewhat confusing ...
Calling method using JavaScript prototype
...he prototype. Your response forces me to create a factory and i'd like to know if there's any way to avoid that.
– R01010010
Dec 24 '14 at 3:09
10
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