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Check if a JavaScript string is a URL
...ed question with an answer:
Javascript regex URL matching
Or this Regexp from Devshed:
function validURL(str) {
var pattern = new RegExp('^(https?:\\/\\/)?'+ // protocol
'((([a-z\\d]([a-z\\d-]*[a-z\\d])*)\\.)+[a-z]{2,}|'+ // domain name
'((\\d{1,3}\\.){3}\\d{1,3}))'+ // OR ip (v4) addre...
Official reasons for “Software caused connection abort: socket write error”
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Possible solution: Ensure that the HttpClient is non-null before reading from the connection.E13222_01
Connection reset by peer.
The connection has been terminated by the peer (server).
Connection reset.
The connection has been either terminated by the client or closed by the server end ...
Find difference between timestamps in seconds in PostgreSQL
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Try:
SELECT EXTRACT(EPOCH FROM (timestamp_B - timestamp_A))
FROM TableA
Details here: EXTRACT.
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Storing Images in DB - Yea or Nay?
...ing system's sendfile() system call to asynchronously send a file directly from the file system to the network interface. Images stored in a database don't benefit from this optimization.
things like web servers, etc, need no special coding or processing to access images in the file system
database...
Visually managing MongoDB documents and collections [closed]
...to keep searching for documents, copy-and-pasting OIDs, etc., especially from a command prompt window (ever tried to "mark" text that wraps multiple lines?)
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Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2
...ata.frame(a = 1:3, b=letters[1:3])
require(sqldf)
a1NotIna2 <- sqldf('SELECT * FROM a1 EXCEPT SELECT * FROM a2')
And the rows which are in both data frames:
a1Ina2 <- sqldf('SELECT * FROM a1 INTERSECT SELECT * FROM a2')
The new version of dplyr has a function, anti_join, for exactly the...
Add a tooltip to a div
...oltip to be clickable - this blurs links and tooltips, preventing the user from knowing whether a highlighted word will 1) give them more information or 2) take them to another page entirely. In general, bad practice.
– sscirrus
Apr 14 '14 at 22:33
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Convert a list of data frames into one data frame
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Use bind_rows() from the dplyr package:
bind_rows(list_of_dataframes, .id = "column_label")
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PostgreSQL, checking date relative to “today”
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select * from mytable where mydate > now() - interval '1 year';
If you only care about the date and not the time, substitute current_date for now()
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MySQL stored procedure vs function, which would I use when?
...d procedures with ordinary SQL, whilst with stored function you can.
e.g. SELECT get_foo(myColumn) FROM mytable is not valid if get_foo() is a procedure, but you can do that if get_foo() is a function. The price is that functions have more limitations than a procedure.
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