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PostgreSQL Crosstab Query
... - not fit for missing attributes
crosstab(text) with 1 input parameter:
SELECT *
FROM crosstab(
'SELECT section, status, ct
FROM tbl
ORDER BY 1,2' -- needs to be "ORDER BY 1,2" here
) AS ct ("Section" text, "Active" int, "Inactive" int);
Returns:
Section | Active | Inacti...
date format yyyy-MM-ddTHH:mm:ssZ
...
One option could be converting DateTime to ToUniversalTime() before converting to string using "o" format. For example,
var dt = DateTime.Now.ToUniversalTime();
Console.WriteLine(dt.ToString("o"));
It will output:
2016-01-31T20:16:01.909234...
How to get the selected index of a RadioGroup in Android
Is there an easy way to get the selected index of a RadioGroup in Android or do I have to use OnCheckedChangeListener to listen for changes and have something that holds the last index selected?
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PHP - iterate on string characters
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Step 1: convert the string to an array using the str_split function
$array = str_split($your_string);
Step 2: loop through the newly created array
foreach ($array as $char) {
echo $char;
}
You can check the PHP docs for more in...
The tilde operator in C
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@MarcusJ Yes, one's complement works for converting signed to unsigned (signed->unsigned). (Note though it's easier to just assign the value to a variable declared differently and lett the compiler worry about it.) But it does not work the other way around (unsig...
jQuery count child elements
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You can use .length with just a descendant selector, like this:
var count = $("#selected li").length;
If you have to use .children(), then it's like this:
var count = $("#selected ul").children().length;
You can test both versions here.
...
How does the const constructor actually work?
...ecognize equivalence of these constants.
Canonicalization:
A process for converting data that has more than one possible representation into a "standard" canonical representation. This can be done to compare different representations for equivalence, to count the number of distinct data structures...
MySQL: Fastest way to count number of rows
...s.
The solution is SQL_CALC_FOUND_ROWS. This is usually used when you are selecting rows but still need to know the total row count (for example, for paging).
When you select data rows, just append the SQL_CALC_FOUND_ROWS keyword after SELECT:
SELECT SQL_CALC_FOUND_ROWS [needed fields or *] FROM t...
Selecting only numeric columns from a data frame
...traightforward, and robust to use on database-back-ended tibbles:
dplyr::select_if(x, is.numeric)
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Selecting element by data attribute
Is there an easy and straight-forward method to select elements based on their data attribute? For example, select all anchors that has data attribute named customerID which has value of 22 .
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