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Using LINQ to concatenate strings
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Real example from my code:
return selected.Select(query => query.Name).Aggregate((a, b) => a + ", " + b);
A query is an object that has a Name property which is a string, and I want the names of all the queries on the selected list, separated by comma...
How to install both Python 2.x and Python 3.x in Windows
...ed Python 2.7.6.
How to...
Start > in the search type in environment select "Edit environment variables to your account"1
Scroll down to Path, select path, click edit.
Add C:\Python27;
so you should have paths to both versions of Python there, but if you don't this you can easily edit it so th...
How many database indexes is too many?
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It depends on the operations that occur on the table.
If there's lots of SELECTs and very few changes, index all you like.... these will (potentially) speed the SELECT statements up.
If the table is heavily hit by UPDATEs, INSERTs + DELETEs ... these will be very slow with lots of indexes since t...
How to find Unused Amazon EC2 Security groups
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If you select all of your security groups in the EC2 console, then press actions -> Delete Security Groups, a popup will appear telling you that you cannot delete security groups that are attached to instances, other security gro...
Getting raw SQL query string from PDO prepared statements
...the principle is the same.
081016 16:51:28 2 Query prepare s1 from 'select * from foo where i = ?'
2 Prepare [2] select * from foo where i = ?
081016 16:51:39 2 Query set @a =1
081016 16:51:47 2 Query execute s1 using @a
2 Execute [2] select...
How to use gradle zip in local system without downloading when using gradle-wrapper
...ip in gradle/wrapper/.
Then, ./gradlew build downloaded local copy of zip and built the project.
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How can I use external JARs in an Android project?
...your JAR files to the libs folder
Now right click on the Jar file and then select Build Path > Add to Build
Path, which will create a folder called 'Referenced Libraries' within your
project
By doing this, you will not
lose your libraries that are being referenced on your
hard drive whenever you...
C# using streams
...treams are kind of mysterious to me. I don't know when to use which stream and how to use them. Can someone explain to me how streams are used?
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Rails filtering array of objects by attribute value
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Try :
This is fine :
@logos = @attachments.select { |attachment| attachment.file_type == 'logo' }
@images = @attachments.select { |attachment| attachment.file_type == 'image' }
but for performance wise you don't need to iterate @attachments twice :
@logos , @images...
Find out what process registered a global hotkey? (Windows API)
...sual Studio\2017\Community\Common7\Tools\spyxx_amd64.exe)
In the menu bar, select Spy -> Log messages... (or hit Ctrl + M)
Check All Windows in System in the Additional Windows frame
Switch to the Messages tab
Click the Clear All button
Select WM_HOTKEY in the listbox, or check Keyboard in Messag...