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In Ruby on Rails, what's the difference between DateTime, Timestamp, Time and Date?
...ave DATE, DATETIME, TIME and TIMESTAMP column data types; just as you have CHAR, VARCHAR, FLOAT and INTEGER.
So, you ask, what's the difference? Well, some of them are self-explanatory. DATE only stores a date, TIME only stores a time of day, while DATETIME stores both.
The difference between DATE...
Hibernate dialect for Oracle Database 11g?
...e getQuerySequencesString() method, that returns this query:
"select sequence_name from user_sequences;"
for which the execution returns an empty result from database).
Using the dialect org.hibernate.dialect.Oracle9iDialect , or greater, solves the problem, due to a di...
postgresql COUNT(DISTINCT …) very slow
...
You can use this:
SELECT COUNT(*) FROM (SELECT DISTINCT column_name FROM table_name) AS temp;
This is much faster than:
COUNT(DISTINCT column_name)
share
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jQuery: select all elements of a given class, except for a particular Id
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Use the :not selector.
$(".thisclass:not(#thisid)").doAction();
If you have multiple ids or selectors just use the comma delimiter, in addition:
(".thisclass:not(#thisid,#thatid)").doAction();
...
MySQL convert date string to Unix timestamp
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Here's an example of how to convert DATETIME to UNIX timestamp:
SELECT UNIX_TIMESTAMP(STR_TO_DATE('Apr 15 2012 12:00AM', '%M %d %Y %h:%i%p'))
Here's an example of how to change date format:
SELECT FROM_UNIXTIME(UNIX_TIMESTAMP(STR_TO_DATE('Apr 15 2012 12:00AM', '%M %d %Y %h:%i%p')),'%m-%d-...
jquery how to empty input field
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On a related note, .val([]) can also unselect any selected option in select list... not so much with .val(''). Best thing about it is it's cross-browser support. P.S: This is an alternative to only other efficient cross-browser solution - $("select option").prop("...
What is the difference between onBlur and onChange attribute in HTML?
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An example to make things concrete. If you have a selection thus:
<select onchange="" onblur="">
<option>....
</select>
the onblur() is called when you navigate away. The onchange() is called when you select a different option from the selection - i.e....
SQL Server Installation - What is the Installation Media Folder?
... Server 2019 Developer version. Was lost with dialog prompted from step 3 "Select installation media". This Andy Leonard blog helped me: 1. Downloaded installation package from SQL Server downloads. 2. Launch downloaded wizard > Select installation type > Download media 3. Right-click on the d...
Code formatting shortcuts in Android Studio for Operation Systems
...System Settings → Keyboard → Shortcuts tab → System → Lock Screen.
Select the row New Accelerator..., then press any special key with the Alpha key (e.g. Shift + L). You should've successfully changed the keyboard shortcut.
Check if the keyboard shortcut now works in Android Studio.
Altern...
How to convert array to SimpleXML
...de);
} else {
$xml_data->addChild("$key",htmlspecialchars("$value"));
}
}
}
// initializing or creating array
$data = array('total_stud' => 500);
// creating object of SimpleXMLElement
$xml_data = new SimpleXMLElement('<?xml version="1.0"?><data>&...