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How to append a newline to StringBuilder
... edited Mar 15 '19 at 16:20
Charles Giguere
4711 silver badge99 bronze badges
answered Dec 3 '15 at 18:00
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postgresql COUNT(DISTINCT …) very slow
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You can use this:
SELECT COUNT(*) FROM (SELECT DISTINCT column_name FROM table_name) AS temp;
This is much faster than:
COUNT(DISTINCT column_name)
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Why so red? IntelliJ seems to think every declaration/method cannot be found/resolved
...(Integer for example) and press ALT + ENTER (or click the light bulb icon)
select Setup JDK from the intentions menu
click on Configure
In my case, the JDK path was incorrect (pointed on /opt/jdk1.7.0_51 instead of /opt/jdk1.7.0_65)
Click on the ... and browse to the right JDK path
Let's...
Why do we need argc while there is always a null at the end of argv?
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...Which is a shame, in a way. If we had int main(char *argv[], int argc, ...), then some programs could just omit the argc because they do not need it. Opposite (needing argc but not argv) is probably never useful in a real program.
– hyde
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Visual Studio immediate window command for Clear All
...ace the mouse cursor in the Immediate Window.
Right click on the mouse and select "Clear All".
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How to use Elasticsearch with MongoDB?
...ng bumped up when you update.
echo "mongodb-10gen hold" | sudo dpkg --set-selections
Start the MongoDB service.
sudo service mongodb start
Your database files default to /var/lib/mongo and your log files to /var/log/mongo.
Create a database through the mongo shell and push some dummy data int...
How can I merge two hashes without overwritten duplicate keys in Ruby?
... and defaults without overwriting the destination hash, you may check with select if the key is already present in the destination hash. Here's the pure Ruby solution without Rails:
options = { "a" => 100, "b" => 200 }
defaults = { "b" => 254, "c" => 300 }
options.merge!(defaults.selec...
Django dynamic model fields
...y constraint, which may be inefficient on some databases.
You will need to select one of the forks, since the official package is no longer maintained and there is no clear leader.
The usage is pretty straightforward:
import eav
from app.models import Patient, Encounter
eav.register(Encounter)
e...
Remove all special characters except space from a string using JavaScript
I want to remove all special characters except space from a string using JavaScript.
11 Answers
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What's best SQL datatype for storing JSON string?
...d as of SQL Server 2005 and should not be used for new development. Use VARCHAR(MAX) or NVARCHAR(MAX) instead
IMAGE, VARBINARY(MAX) : IMAGE is deprecated just like TEXT/NTEXT, and there's really no point in storing a text string into a binary column....
So that basically leaves VARCHAR(x) or NVARC...