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MySQL DISTINCT on a GROUP_CONCAT()
I am doing SELECT GROUP_CONCAT(categories SEPARATOR ' ') FROM table . Sample data below:
6 Answers
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sed error: “invalid reference \1 on `s' command's RHS”
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Sorry. The edit raises the error: sed: -e expression #7, char 58: Invalid range end. @Denis' answer works.
– JJD
May 19 '13 at 18:29
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Core dumped, but core file is not in the current directory?
...ore_pattern is used to specify a core dumpfile pattern name.
If the first character of the pattern is a '|', the kernel will treat
the rest of the pattern as a command to run. The core dump will be
written to the standard input of that program instead of to a file.
Instead of writing the core du...
Add disabled attribute to input element using Javascript
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Working code from my sources:
HTML WORLD
<select name="select_from" disabled>...</select>
JS WORLD
var from = jQuery('select[name=select_from]');
//add disabled
from.attr('disabled', 'disabled');
//remove it
from.removeAttr("disabled");
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Join between tables in two different databases?
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Yes, assuming the account has appropriate permissions you can use:
SELECT <...>
FROM A.table1 t1 JOIN B.table2 t2 ON t2.column2 = t1.column1;
You just need to prefix the table reference with the name of the database it resides in.
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The Ruby %r{ } expression
...y, for legibility.
Edit:
Note that you can use almost any non-alphabetic character pair instead of '{}'.
These variants work just as well:
%r!/home/user!
%r'/home/user'
%r(/home/user)
Edit 2:
Note that the %r{}x variant ignores whitespace, making complex regexps more readable. Example from Git...
Difference between \n and \r?
...-line instead
in Windows (and many old OSs), the code for end of line is 2 characters, \r\n, in this order
as a (surprising;-) consequence (harking back to OSs much older than Windows), \r\n is the standard line-termination for text formats on the Internet
for electromechanical teletype-like "termin...
How do I get the value of text input field using JavaScript?
... 'searchtext' in your page.
Method 5:
Use the powerful document.querySelector('selector').value which uses a CSS selector to select the element
For example, document.querySelector('#searchTxt').value; selected by id
document.querySelector('.searchField').value; selected by class
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Xcode + remove all breakpoints
...l breakpoints.
In Xcode4 press CMD(⌘)+6, in Xcode3 press CMD(⌘)+ALT+B.
Select all breakpoints with CMD(⌘)+A and delete them, like deleting text, with backspace.
There's no step 3 :)
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MySQL - SELECT WHERE field IN (subquery) - Extremely slow why?
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Rewrite the query into this
SELECT st1.*, st2.relevant_field FROM sometable st1
INNER JOIN sometable st2 ON (st1.relevant_field = st2.relevant_field)
GROUP BY st1.id /* list a unique sometable field here*/
HAVING COUNT(*) > 1
I think st2.relevant_...