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MySQL Creating tables with Foreign Keys giving errno: 150
... of table test/t2:
FOREIGN KEY (t1_id) REFERENCES t1 (id)):
Cannot find an index in the referenced table where the
referenced columns appear as the first columns, or column types
in the table and the referenced table do not match for constraint.
It says that the problem is it can’t find an index...
How to make an array of arrays in Java
...lements and there are specialized Collections for different functionality (index-based lookup, sorting, uniqueness, FIFO-access, concurrency etc.).
While it's of course good and important to know about Arrays and their usage, in most cases using Collections makes APIs a lot more manageable (which i...
What exactly are iterator, iterable, and iteration?
...n iterator, or which defines a __getitem__ method that can take sequential indexes starting from zero (and raises an IndexError when the indexes are no longer valid). So an iterable is an object that you can get an iterator from.
An iterator is an object with a next (Python 2) or __next__ (Python 3...
How do 20 questions AI algorithms work?
Simple online games of 20 questions powered by an eerily accurate AI.
5 Answers
5
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How to get a string after a specific substring?
...
s1 = "hello python world , i'm a beginner "
s2 = "world"
print s1[s1.index(s2) + len(s2):]
If you want to deal with the case where s2 is not present in s1, then use s1.find(s2) as opposed to index. If the return value of that call is -1, then s2 is not in s1.
...
How do I use su to execute the rest of the bash script as that user?
...run chsh for the other users. My issue is listed here at stackoverflow.com/q/15307289/80353 How do I adapt your answer in my situation?
– Kim Stacks
Mar 10 '13 at 3:32
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What does “WARN Could not determine content-length of response body.” mean and how to I get rid of i
...
Asked the same question to one of Rails-Core's members:
https://twitter.com/luislavena/status/108998968859566080
And the answer:
https://twitter.com/tenderlove/status/108999110136303617
ya, it's fine. Need to clean it up, but nothing...
SQL injection that gets around mysql_real_escape_string()
...et_charset() / $mysqli->set_charset() / PDO's DSN charset parameter (in PHP ≥ 5.3.6)
OR
Don't use a vulnerable character set for connection encoding (you only use utf8 / latin1 / ascii / etc)
You're 100% safe.
Otherwise, you're vulnerable even though you're using mysql_real_escape_string().....
“var” or no “var” in JavaScript's “for-in” loop?
...ave more than one for-loop in one scope? You will either have to reuse the index (no var), or you will have to declare lots and lots of new variables (j, k, l, m, …) which you will never use again.
– armin
Sep 2 '15 at 5:14
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How to loop backwards in python? [duplicate]
...-1) instead of range(10, 0, -1). because range(10, 0, -1) will stop at the index 0, as a result, the index 0 value will not print.
– Hatim
Nov 30 '15 at 15:03
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