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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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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...
What is the fundamental difference between WebSockets and pure TCP?
...easier to send messages over the wire via the Application Layer instead of raw bytes at the Transport Layer.
Underlying WebSockets is TCP, it's just abstracted away for simplicity.
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Strange out of memory issue while loading an image to a Bitmap object
... BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight ...
How can prepared statements protect from SQL injection attacks?
...ample shows it (all examples in PHP/Mysql):
$expected_data = 1;
$query = "SELECT * FROM users where id=$expected_data";
will produce a regular query
SELECT * FROM users where id=1
while this code
$spoiled_data = "1; DROP TABLE users;"
$query = "SELECT * FROM users where id=$spoiled_da...
XPath to select Element by attribute value
...he parts in [ ]) shouldn't have slashes immediately before them. Also, to select the Employee element itself, you should leave off the /text() at the end or otherwise you'd just be selecting the whitespace text values immediately under the Employee element.
//Employee[@id='4']
Edit: As Jens poin...
In Angular, I need to search objects in an array
...ById')($scope.fish, fish_id);
console.log(found);
$scope.selected = JSON.stringify(found);
}
}]);
If there are any questions just let me know.
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How can I set the default value for an HTML element?
I thought that adding a "value" attribute set on the <select> element below would cause the <option> containing my provided "value" to be selected by default:
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How to check Oracle database for long running queries
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This one shows SQL that is currently "ACTIVE":-
select S.USERNAME, s.sid, s.osuser, t.sql_id, sql_text
from v$sqltext_with_newlines t,V$SESSION s
where t.address =s.sql_address
and t.hash_value = s.sql_hash_value
and s.status = 'ACTIVE'
and s.username <> 'SYSTEM'
ord...
Reset auto increment counter in postgres
... Does anyone know why ALTER SEQUENCE product_id_seq RESTART WITH (SELECT MAX(id) from product); Doesn't work? The only way I found is to use two separate queries.
– Chris Huang-Leaver
Dec 20 '18 at 3:14
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