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SQL, Postgres OIDs, What are they and why are they useful?

... OIDs basically give you a built-in id for every row, contained in a system column (as opposed to a user-space column). That's handy for tables where you don't have a primary key, have duplicate rows, etc. For example, if you have a t...
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What does value & 0xff do in Java?

... that notation? x isn't a number or a hex number? – Callat Dec 5 '16 at 18:56 3 @KazRodgers - The...
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PostgreSQL - fetch the row which has the Max value for a column

I'm dealing with a Postgres table (called "lives") that contains records with columns for time_stamp, usr_id, transaction_id, and lives_remaining. I need a query that will give me the most recent lives_remaining total for each usr_id ...
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How to check if a String contains only ASCII?

The call Character.isLetter(c) returns true if the character is a letter. But is there a way to quickly find if a String only contains the base characters of ASCII? ...
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Parsing CSV files in C#, with header

... Let a library handle all the nitty-gritty details for you! :-) Check out FileHelpers and stay DRY - Don't Repeat Yourself - no need to re-invent the wheel a gazillionth time.... You basically just need to define that shape of your data - the fi...
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Introducing FOREIGN KEY constraint may cause cycles or multiple cascade paths - why?

...igure out what's happening. I have a Card entity which contains Sides (usually 2) - and both Cards and Sides have a Stage. I'm using EF Codefirst migrations and the migrations are failing with this error: ...
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Differences between distribute, distutils, setuptools and distutils2?

...e Foundation just adds credence to it. The Project Summaries page is especially relevant here. Summary of tools: Here's a summary of the Python packaging landscape: Supported tools: distutils is still the standard tool for packaging in Python. It is included in the standard library (Python 2 an...
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Is there a version control system for database structure changes?

...keeps track of your current db version. To migrate up, you run a command called "db:migrate" which looks at your version and applies the needed scripts. You can migrate down in a similar way. The migration scripts themselves are kept in a version control system -- whenever you change the database ...
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How to discard local changes in an SVN checkout?

...er changes are not required : """Rest of the changes I made, were for basically debugging, and are no longer required.""" :) – Cédric Julien Feb 27 '12 at 10:54 1 ...
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How can I search for a commit message on GitHub?

Not in a Git repository , but rather in GitHub specifically - how do I search just the commit messages of a specific repository/branch? ...