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Why does NULL = NULL evaluate to false in SQL server

... I disagree that null signifies "unknown". What it actually means is "no data". That might be used to represent the case where information is not known, but it is actually more likely to be used to indicate that something doesn't exist. To continue your example: What is Frank's m...
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Rename multiple files by replacing a particular pattern in the filenames using a shell script [dupli

...ho "$f" | sed s/IMG/VACATION/)"; done In this example, I am assuming that all your image files contain the string IMG and you want to replace IMG with VACATION. The shell automatically evaluates *.jpg to all the matching files. The second argument of mv (the new name of the file) is the output of t...
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How does Java handle integer underflows and overflows and how would you check for it?

... long or maybe java.math.BigInteger. The last one doesn't overflow, practically, the available JVM memory is the limit. If you happen to be on Java8 already, then you can make use of the new Math#addExact() and Math#subtractExact() methods which will throw an ArithmeticException on overflow. pub...
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How can I use a carriage return in a HTML tooltip?

...>link with tip</a> Firefox won't display multi-line tooltips at all though - it will replace the newlines with nothing. share | improve this answer | follow ...
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How to change a nullable column to not nullable in a Rails migration?

...s: # Make sure no null value exist MyModel.where(date_column: nil).update_all(date_column: Time.now) # Change the column to not allow null change_column :my_models, :date_column, :datetime, null: false share | ...
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How to add Google Analytics Tracking ID to GitHub Pages

... I have added them, however Google analytics say the Tracking is not installed. My page as specified in G-Analytics is http://avi-aryan.github.io – Avi Jul 15 '13 at 12:33 1 ...
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How are feature_importances in RandomForestClassifier determined?

...d in [1] (often cited, but unfortunately rarely read...). It is sometimes called "gini importance" or "mean decrease impurity" and is defined as the total decrease in node impurity (weighted by the probability of reaching that node (which is approximated by the proportion of samples reaching that no...
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How to grep Git commit diffs or contents for a certain word?

In a Git code repository I want to list all commits that contain a certain word. I tried this 8 Answers ...
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Avoid trailing zeroes in printf()

...ing your number is in the variable num, the following function will remove all but the first N decimals, then strip off the trailing zeros (and decimal point if they were all zeros). char str[50]; sprintf (str,"%.20g",num); // Make the number. morphNumericString (str, 3); : : void morphNumericS...
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Conceptually, how does replay work in a game?

... I think your initial thought was correct. To create a replay, you store all input received from the user (along with the frame number at which it was received) along with the initial seeds of any random number generators. To replay the game, you reset your PRNGs using the saved seeds and feed th...