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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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Show data on mouseover of circle
...and you don't need the mousehandler. The code would be something like
vis.selectAll("circle")
.data(datafiltered).enter().append("svg:circle")
...
.append("svg:title")
.text(function(d) { return d.x; });
If you want fancier tooltips, you could use tipsy for example. See here for an ex...
Best way to check if object exists in Entity Framework?
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hi. how can we check if it exists and after that select all its data?
– virtouso
Apr 7 '15 at 1:27
1
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Why there can be only one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT clause?
...pdated) values(null, null);
Query OK, 1 row affected (0.06 sec)
mysql> select * from t5;
+----+---------------------+---------------------+
| id | stamp_created | stamp_updated |
+----+---------------------+---------------------+
| 2 | 2009-04-30 09:44:35 | 2009-04-30 09:44:35 |
+...
How can I view the shared preferences file using Android Studio?
...in. 4. Start Android Emulator (in my case API 24) 5. Launch stetho-sample (select it from run configuration menu next to green arrow 6. On your PC open latest Chrome browser 7. go by chrome://inspect address 8. chose your emulator in list. 9. In opened window go to Resources tab. 10. Find your share...
How to format an inline code in Confluence?
... {{example}}.
If you're using Confluence 4.x or higher, you can also just select the "Preformatted" option from the paragraph style menu. Please note that will apply to the entire line.
Full reference here.
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String concatenation in MySQL
...most DBMSs use of + or || for concatenation. It uses the CONCAT function:
SELECT CONCAT(first_name, " ", last_name) AS Name FROM test.student
As @eggyal pointed out in comments, you can enable string concatenation with the || operator in MySQL by setting the PIPES_AS_CONCAT SQL mode.
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Why does installing Nokogiri on Mac OS fail with libiconv is missing?
...ed to install xCode command tools to allow you to install libiconv.
xcode-select --install
then install a newer version of libiconv
brew install libiconv
then install your gem
gem install nokogiri -- --with-iconv-dir=/usr/local/Cellar/libiconv/1.14
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Does the join order matter in SQL?
...t matter. The queries will return same results, as long as you change your selects from SELECT * to SELECT a.*, b.*, c.*.
For (LEFT, RIGHT or FULL) OUTER joins, yes, the order matters - and (updated) things are much more complicated.
First, outer joins are not commutative, so a LEFT JOIN b is no...
Parallel.ForEach() vs. foreach(IEnumerable.AsParallel())
...the AsParallel() call, like:
var fibonacciNumbers = numbers.AsParallel().Select(n => ComputeFibonacci(n));
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