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Why use multiple columns as primary keys (composite primary key)
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Your understanding is correct.
You would do this in many cases. One example is in a relationship like OrderHeader and OrderDetail. The PK in OrderHeader might be OrderNumber. The PK in OrderDetail might be OrderNumber AND LineNumber. ...
Download file from web in Python 3
...`; this step can't be used if data is binary
The easiest way to download and save a file is to use the urllib.request.urlretrieve function:
import urllib.request
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# Download the file from `url` and save it locally under `file_name`:
urllib.request.urlretrieve(url, file_name)
import urllib.req...
Postgresql GROUP_CONCAT equivalent?
I have a table and I'd like to pull one row per id with field values concatenated.
7 Answers
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Android - Set max length of logcat messages
...e that it considers to be "too long". This happens both inside of Eclipse and when running logcat on the command line using adb -d logcat , and is truncating some important debugging messages.
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How to select all instances of selected region in Sublime Text
Is there a shortcut key or single-step menu option to find and select all instances of a highlighted selection in Sublime Text?
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Why is UICollectionViewCell's outlet nil?
...ICollectionViewCell in Interface Builder, binded views on it to the class, and then when I want to use and set a string to the label on the string, tha label has a nil value.
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Update just one gem with bundler
I use bundler to manage dependencies in my rails app, and I have a gem hosted in a git repository included as followed:
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Remove all files except some from a directory
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find . -type f -not -name '*txt' -print0 | xargs -0 rm --
The print0 and -0 combination is needed if there are spaces in any of the filenames that should be deleted.
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onIabPurchaseFinished never called.
I've been trying to set up in-app billing for my first app, and have been using the android.test.purchased sku. The purchase come through, and I manage to get the SKU into my inventory, but, as the title says, onIabPurchaseFinished, is never called.
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What is a build tool?
For past 4 years, I have been programming with Eclipse (for Java), and Visual Studio Express (for C#). The IDEs mentioned always seemed to provide every facility a programmer might ask for (related to programming, of course).
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