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Rails raw SQL example
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You can do this:
sql = "Select * from ... your sql query here"
records_array = ActiveRecord::Base.connection.execute(sql)
records_array would then be the result of your sql query in an array which you can iterate through.
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Get the value of a dropdown in jQuery
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$('#Crd').val() will give you the selected value of the drop down element. Use this to get the selected options text.
$('#Crd option:selected').text();
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Click button copy to clipboard using jQuery
...browsers because most browsers have the ability to programmatically copy a selection of text to the clipboard using document.execCommand("copy") that works off a selection.
As with some other actions in a browser (like opening a new window), the copy to clipboard can only be done via a specific use...
Get records with max value for each group of grouped SQL results
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There's a super-simple way to do this in mysql:
select *
from (select * from mytable order by `Group`, age desc, Person) x
group by `Group`
This works because in mysql you're allowed to not aggregate non-group-by columns, in which case mysql just returns the first row. T...
how to emulate “insert ignore” and “on duplicate key update” (sql merge) with postgresql?
... two queries, one for INSERT and one for UPDATE (as an appropriate join/subselect of course - no need to write your main filter twice)
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Create a unique number with javascript time
...oString(36) + Math.random().toString(36).substr(2) That will give you a 19 character alphanumeric string which is a decent amount of entropy. Albeit half of it is predictable.
– Erik Pukinskis
Jul 30 '17 at 23:32
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Reshaping data.frame from wide to long format
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Here is another example showing the use of gather from tidyr. You can select the columns to gather either by removing them individually (as I do here), or by including the years you want explicitly.
Note that, to handle the commas (and X's added if check.names = FALSE is not set), I am also us...
Measure the time it takes to execute a t-sql query
... to just grab the current date and time.
In SQL Server Management Studio
SELECT GETDATE();
SELECT /* query one */ 1 ;
SELECT GETDATE();
SELECT /* query two */ 2 ;
SELECT GETDATE();
To calculate elapsed times, you could grab those date values into variables, and use the DATEDIFF function:
DECL...
What's the fastest algorithm for sorting a linked list?
...is best, followed by Quicksort and Mergesort. Sediment sort, bubble sort, selection sort perform very badly.
A COMPARATIVE STUDY OF LINKED LIST SORTING ALGORITHMS
by Ching-Kuang Shene
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.31.9981
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Why shouldn't I use mysql_* functions in PHP?
... 5.5 and above)
$link = mysql_connect('localhost', 'user', 'pass');
mysql_select_db('testdb', $link);
mysql_set_charset('UTF-8', $link);
With PDO: All you need to do is create a new PDO object. The constructor accepts parameters for specifying the database source PDO's constructor mostly takes fo...