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Postgresql aggregate array
...
Use array_agg: http://www.sqlfiddle.com/#!1/5099e/1
SELECT s.name, array_agg(g.Mark) as marks
FROM student s
LEFT JOIN Grade g ON g.Student_id = s.Id
GROUP BY s.Id
By the way, if you are using Postgres 9.1, you don't need to repeat the columns on SELECT to GROUP BY,...
How do I check to see if a value is an integer in MySQL?
...e REGEXP operator, matching the string to a regular expression. Simply do
select field from table where field REGEXP '^-?[0-9]+$';
this is reasonably fast. If your field is numeric, just test for
ceil(field) = field
instead.
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Importing a GitHub project into Eclipse
...ries")
Eclipse with GitHub
EGit tutorial
Copy the URL from GitHub and select in Eclipse from the menu the
File → Import → Git → Projects from Git
If the Git repo isn't cloned yet:
In> order to checkout a remote project, you will have to clone its repository first.
Open the E...
Tri-state Check box in HTML?
...lternative would be to play with the checkbox transparency
for the "some selected" state (as Gmail does used to
do in previous versions). It will require some javascript and a CSS
class. Here I put a particular example that handles a list with
checkable items and a checkbox that allows to se...
Selectively revert or checkout changes to a file in Git?
... @Jan Do other version control systems' revert command allow you to select which changes within a file are reverted? Genuinely asking, as I only have experience with CVS and Git. In Git, git checkout -- path/to/file is a single command that reverts all changes in that file, but this is not th...
Vim indent xml file
... that you don't have to alter your vimrc file. Plus it is easier to format select portions of the XML file (something I happen to do a lot).
First, highlight the XML you want to format.
Then, in normal mode, type ! xmllint --format -
Your command-line at the bottom will look like this:
:'<,'&...
Conversion failed when converting date and/or time from character string while inserting datetime
...s the recommend date/time data types for SQL Server 2008 or newer anyway.
SELECT
CAST('02-21-2012 6:10:00 PM' AS DATETIME2), -- works just fine
CAST('01-01-2012 12:00:00 AM' AS DATETIME2) -- works just fine
Don't ask me why this whole topic is so tricky and somewhat confusing - that...
How make Eclipse/EGit recognize existing repository information after update?
...ositories" dialogue, under Search criteria, enter the workspace directory, select "Look for nested repositores", and hit Search:
Select the repositories you want to add and click OK
"Share" each of the projects again using "use or create repository"
Open you existing project in Eclipse's Projec...
Open a folder using Process.Start
...er. (Thanks to @binki.)
This solution won't work for opening a folder and selecting an item, since there doesn't seem a verb for that.
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How do you count the number of occurrences of a certain substring in a SQL varchar?
...mparing the lengths
Declare @string varchar(1000)
Set @string = 'a,b,c,d'
select len(@string) - len(replace(@string, ',', ''))
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