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NULL values inside NOT IN clause
...t I thought were identical queries one using a not in where constraint and the other a left join . The table in the not in constraint had one null value (bad data) which caused that query to return a count of 0 records. I sort of understand why but I could use some help fully grasping the con...
boost::flat_map and its performance compared to map and unordered_map
...haven't been able to find any performance comparisons. How does it compare and what are the best use cases for it?
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Should I use pt or px?
What is the difference between pt and px in CSS? Which one should I use and why?
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Getting random numbers in Java [duplicate]
I would like to get a random value between 1 to 50 in Java.
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Linux command (like cat) to read a specified quantity of characters
Is there a command like cat in linux which can return a specified quantity of characters from a file?
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How to create Java gradle project
How to create Java Gradle project from command line?
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How do DATETIME values work in SQLite?
I’m creating Android apps and need to save date/time of the creation record. The SQLite docs say, however, "SQLite does not have a storage class set aside for storing dates and/or times" and it's "capable of storing dates and times as TEXT, REAL, or INTEGER values".
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Upgrade python in a virtualenv
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Did you see this? If I haven't misunderstand that answer, you may try to create a new virtualenv on top of the old one. You just need to know which python is going to use your virtualenv (you will need to see your virtualenv version).
If your virtualenv is install...
How to get users to read error messages?
...ind yourself at a high risk that users will not read your carefully worded and enlightening error messages, but just click on the first button available with a shrug of frustration.
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A simple scenario using wait() and notify() in java
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The wait() and notify() methods are designed to provide a mechanism to allow a thread to block until a specific condition is met. For this I assume you're wanting to write a blocking queue implementation, where you have some fixed size ...