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How to concatenate strings of a string field in a PostgreSQL 'group by' query?
... ') AS semi_colon_separated_names FROM things;
But this will be a syntax error:
SELECT string_agg(name, '; ' ORDER BY name) AS semi_colon_separated_names FROM things;
--> ERROR: syntax error at or near "ORDER"
Tested on PostgreSQL 8.3.
CREATE FUNCTION string_agg_transfn(text, text, text)
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How do I verify/check/test/validate my SSH passphrase?
... ssh-add requires admin rights on the machine, I think. I am getting an error: "Could not open a connection to your authentication agent."
– IgorGanapolsky
Feb 12 '14 at 21:15
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Setting up FTP on Amazon Cloud Server [closed]
...hat means that after rebooting your EC2 instance, you'll feel a moment of terror when FTP seems to be broken - but in reality, it's just not running!. Here's a handy way to fix that:
> sudo chkconfig --level 345 vsftpd on
Alternatively, if you are using redhat, another way to manage your serv...
Why does this method print 4?
I was wondering what happens when you try to catch an StackOverflowError and came up with the following method:
7 Answers
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django admin - add custom form fields that are not part of the model
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@sthzg, Because it's not correct. It gives me the error: YourModelAdmin.list_display[0], 'extra_field' is not a callable or an attribute of 'YourModelAdmin' or found in the model 'YourModel'.
– Cerin
Jun 13 '16 at 15:39
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Writing a git post-receive hook to deal with a specific branch
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Sorry to bring up an old thread, but I'm getting an error at the if statement. fatal: the remote end hung up unexpectedly. error: error in the sideband demultiplexer. It will echo the $branch outside the if statement.
– gin93r
Apr 7 '14 a...
Using node.js as a simple web server
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Note that fs.exists() is also deprecated now. Catch the error on the fs.stat() rather than creating a race condition.
– Matt
Feb 1 '17 at 5:26
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Garbage collector in Android
...gc().
I tried to create Bitmaps, but was always getting "VM out of memory error". But, when I called System.gc() first, it was OK.
When creating bitmaps, Android often fails with out of memory errors, and does not try to garbage collect first. Hence, call System.gc(), and you have enough memory to...
Compare double to zero using epsilon
...ook at the context. It may be that epsilon is a reasonable estimate of the error in the calculation that produced someValue, and it may be that it isn't.
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How do I get jQuery to select elements with a . (period) in their ID?
... @olga said, the answer isn't legal any more. Specifically, you'll get an error message "Uncaught Error: Syntax error, unrecognized expression: div[id=foo bar]"
– James Moore
Aug 24 '17 at 15:19
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