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Troubleshooting “Illegal mix of collations” error in mysql

...ery. Here is an example that uses the COLLATE clause: SELECT * FROM table ORDER BY key COLLATE latin1_general_ci; Another option is to use the BINARY operator: BINARY str is the shorthand for CAST(str AS BINARY). Your solution might look something like this: SELECT * FROM table WHERE BINAR...
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What are the differences between Helper and Utility classes?

...becoming useless. Examples: Vector3, RandomNumberGenerator, StringMatcher, etc... A "helper" seems to be any class whose design is to aid another class. These may or may not depend on your project. If you're creating a GameNetworkClient class, you could say the GameNetworkConnection class is a 'he...
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Undefined reference to `pow' and `floor'

...u can now see, functions pow, floor are linked to GLIBC_2.2.5. Parameters order is important too, unless your system is configured to use shared librares by default, my system is not, so when I issue: $ gcc -lm fib.o fib.o: In function `fibo': fib.c:(.text+0x57): undefined reference to `pow' fib.c...
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sed command with -i option (in-place editing) works fine on Ubuntu but not Mac [duplicate]

... Oh, and if you don't want the backup, run rm -f /etc/hosts.bak after running the sed. That's simpler than trying to work out which variant of sed you have installed or other gizmos I've seen suggested. I hope you keep the file under version control (or otherwise backed up...
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What is the difference between UNION and UNION ALL?

... UNION removes duplicates, whereas UNION ALL does not. In order to remove duplicates the result set must be sorted, and this may have an impact on the performance of the UNION, depending on the volume of data being sorted, and the settings of various RDBMS parameters ( For Oracle PG...
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Is System.nanoTime() completely useless?

... code that uses nanoTime() for timed blocking, interval waiting, timeouts, etc. should preferably treat negative time differences (timeouts) as zeros rather than throw exceptions. This practice is also preferable because it is consistent with the behaviour of all timed wait methods in all classes in...
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Conventions for exceptions or error codes

...tion can then contain code to check whether the file exists, or is locked, etc) share | improve this answer | follow | ...
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How to initialize log4j properly?

...sed to initialize itself, which loggers / appenders got configured and how etc. The configuration file can be a java properties file or an xml file. Here is a sample of the properties file format taken from the log4j intro documentation page: log4j.rootLogger=debug, stdout, R log4j.appender.stdo...
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Skip List vs. Binary Search Tree

...th comparable performance to a balanced tree). I find that implementing in-order traversal (forwards and backwards) is far simpler because a skip-list effectively has a linked list inside its implementation. share |...
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Run a PostgreSQL .sql file using command line arguments

...tements in them and need to run these inserts on my PostgreSQL database in order to add them to a table. The files are that large that it is impossible to open them and copy the INSERT statements into an editor window and run them there. I found on the Internet that you can use the following by navi...