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Cannot add or update a child row: a foreign key constraint fails
... not sure what the downvote is for; my answer is perfectly valid and correct.
– Brian Driscoll
Feb 15 '11 at 15:20
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Read and write a String from text file
I need to read and write data to/from a text file, but I haven't been able to figure out how.
21 Answers
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What's is the difference between include and extend in use case diagram?
What is the difference between include and extend in a use case diagram ?
19 Answers
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Detect if a page has a vertical scrollbar?
... +1 but for the sake of exactness, this only checks whether the content expands further than the viewport. If the overflow property of the body is set to hidden somewhere along the line, it won't work. Setting hidden on a body is extremely rare, though.
– Pekka
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Remove multiple whitespaces
I'm getting $row['message'] from a MySQL database and I need to remove all whitespace like \n \t and so on.
15 Answer...
MySQL maximum memory usage
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MySQL's maximum memory usage very much depends on hardware, your settings and the database itself.
Hardware
The hardware is the obvious part. The more RAM the merrier, faster disks ftw. Don't believe those monthly or weekly news letters though. MySQL doesn't scale linear - not even on Oracle hard...
How do I interpret precision and scale of a number in a database?
...rget that if you're using a system that allows you to pre-define precision and scale of an input for a percentage in something like Microsoft Access, you must consider the percent as it's whole number form. In this case, 25.5% would require precision 4 and scale of 3 (not one) since we have to cons...
Firing events on CSS class changes in jQuery
...that way, when the event is triggered, those events can all happen at once and run their respective functionality. for instance, if i have one object that changes from red to blue and three objects waiting for it to change, when it changes, i can just trigger the changeColor event, and all those obj...
Why doesn't this code simply print letters A to Z?
... convention when dealing with arithmetic operations on character variables and not C's.
For example, in Perl 'Z'+1 turns into 'AA', while in C 'Z'+1 turns into '[' ( ord('Z') == 90, ord('[') == 91 ).
Note that character variables can be incremented but not decremented and even so only plain ASCII ch...
Undefined reference to static class member
...ion creates a scoped integer constant which you can't take the address of, and vector takes a reference param.
– Evan Teran
Nov 7 '08 at 18:08
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