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How to add column if not exists on PostgreSQL?
...statement:
DO $$
BEGIN
BEGIN
ALTER TABLE <table_name> ADD COLUMN <column_name> <column_type>;
EXCEPTION
WHEN duplicate_column THEN RAISE NOTICE 'column <column_name> already exists in <table_name>.';
END;
END;
$$
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API vs. Webservice [closed]
...s don't necessarily use HTTP, but this is almost always the case and is usually assumed unless mentioned otherwise.
For examples of web services specifically, see SOAP, REST, and XML-RPC. For an example of another type of API, one written in C for use on a local machine, see the Linux Kernel API.
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Force to open “Save As…” popup open at text link click for PDF in HTML
... the time of this comment, I've tested it on Chrome, Opera, Edge, Mozilla. All latest. Is working on all except on Mozilla.
– S.I.
Sep 29 '17 at 5:07
7
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Node.js: what is ENOSPC error and how to solve?
... memory, which is unswappable. So, assuming you set the max at 524288, and all were used (improbable), you'd be using approx. 256MB/512MB of 32-bit/64-bit kernel memory.
– Murali Krishna
Apr 5 '17 at 11:19
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Disable Drag and Drop on HTML elements?
...e :active pseudo-class being applied to the element. This means I can't really use it for my links.
– Andy E
Oct 6 '11 at 11:28
3
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Make UINavigationBar transparent
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Undoing the effect for me only partially works. Because after I do this, my tableviews all have headers that are too large. App-wide, which is weird. (I only want this effect for one controller that I push on the stack.)
– Henning
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Fastest Way to Serve a File Using PHP
...erywhere.
Using the X-SendFile header
As documented by others it's actually the best way. The basis is that you do your access control in php and then instead of sending the file yourself you tell the web server to do it.
The basic php code is :
header("X-Sendfile: $file_name");
header("Conten...
Why are data transfer objects (DTOs) an anti-pattern?
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Some projects have all data twice. Once as domain objects, and once as data transfer objects.
This duplication has a huge cost, so the architecture needs to get a huge benefit from this separation to be worth it.
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Setting a system environment variable from a Windows batch file?
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The XP Support Tools (which can be installed from your XP CD) come with a program called setx.exe:
C:\Program Files\Support Tools>setx /?
SETX: This program is used to set values in the environment
of the machine or currently logged on user using one of three...
Why have header files and .cpp files? [closed]
...dencies so that code that uses the header doesn't necessarily need to know all the details of the implementation and any other classes/headers needed only for that. This will reduce compilation times and also the amount of recompilation needed when something in the implementation changes.
It's not ...