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What does mysql error 1025 (HY000): Error on rename of './foo' (errorno: 150) mean?
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You usually get this error if your tables use the InnoDB engine. In that case you would have to drop the foreign key, and then do the alter table and drop the column.
But the tricky part is that you can't drop the foreign key using...
Does the JVM prevent tail call optimizations?
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This post: Recursion or Iteration? might help.
In short, tail call optimization is hard to do in the JVM because of the security model and the need to always have a stack trace available. These requirements could in theory be supported, but it would probably require a new bytecode (see J...
Migration: Cannot add foreign key constraint
...signed();
$table->string('priority_name');
$table->smallInteger('rank');
$table->text('class');
$table->timestamps('timecreated');
});
Schema::table('priorities', function($table) {
$table->foreign('user_id')->references('id')->on('...
How to uncompress a tar.gz in another directory
...specific directory, you can simply cd into your target directory prior to calling tar; then you will have to give a complete path to your archive, of course. You can do this in a scoping subshell to avoid influencing the surrounding script:
mkdir foo
(cd foo; tar -xzf ../bar.tar.gz) # instead of ...
Are there legitimate uses for JavaScript's “with” statement?
...ous as to how I might make effective use of with , while avoiding its pitfalls.
31 Answers
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SQL to determine minimum sequential days of access?
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@Artem: That was what I initially thought but when I thought about it, if you have an index on (UserId, CreationDate), the records will show up consecutively in the index and it should perform well.
– Mehrdad Afshari
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How do I adb pull ALL files of a folder present in SD Card
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The scripts will start in the top folder and recursively go down and find all the "*.jpg" files and pull them from your phone to the current directory.
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What's the purpose of using braces (i.e. {}) for a single-line if or loop?
...le is editor-agnostic beyond what you need, but not beyond what people actually use to edit C++. Hence "defensive".
– Steve Jessop
Aug 30 '12 at 10:11
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Android-java- How to sort a list of objects by a certain value within the object
...e next so Im always missing something :p you know how it goes......jack of all trades but a master of none lol
– James andresakis
Feb 2 '12 at 21:02
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Python speed testing - Time Difference - milliseconds
...e timedelta! For timing purposes always use c.total_seconds().
You can do all sorts of maths with datetime.timedelta, eg:
>>> c / 10
datetime.timedelta(0, 0, 431654)
It might be more useful to look at CPU time instead of wallclock time though ... that's operating system dependant though...