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Why can't a text column have a default value in MySQL?
... I try to recreate the table locally with the obvious default (based on a select of unique values for that column) and end up receiving the oh-so-useful BLOB/TEXT column can't have a default value.
Again, not maintaining basic compatability across platforms is unacceptable and is a bug.
How to ...
Generate a random alphanumeric string in Cocoa
...i=0; i<len; i++) {
[randomString appendFormat: @"%C", [letters characterAtIndex: arc4random_uniform([letters length])]];
}
return randomString;
}
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Filtering for empty or NULL names in a queryset
...null, not-empty alias field. The generated SQL would look something like:
SELECT * FROM Name WHERE alias IS NOT NULL AND alias != ""
You can also pass multiple arguments to a single call to exclude, which would ensure that only objects that meet every condition get excluded:
Name.objects.exclude...
Java RegEx meta character (.) and ordinary dot?
In Java RegEx, how to find out the difference between . (dot) the meta character and the normal dot as we using in any sentence. How to handle this kind of situation for other meta characters too like ( * , + , \d ,...)
...
How to inspect the return value of a function in GDB?
...ue -- given the program
int fun() {
return 42;
}
int main( int argc, char *v[] ) {
fun();
return 0;
}
You can debug it as such --
(gdb) r
Starting program: /usr/home/hark/a.out
Breakpoint 1, fun () at test.c:2
2 return 42;
(gdb) finish
Run till exit from #0 fun () a...
Apache POI Excel - how to configure columns to be expanded?
...e best way we found was to loop over each row in the col, find the longest char length and multiply by x + add a buffer. X use trial and error to see what fits but it should be a average width of a char. Without font I don't believe you can actually get it right but we get pretty close. Otherwise yo...
How to pull a random record using Django's ORM?
...on't know about other databases).
order_by('?')[:N] will be translated to SELECT ... FROM ... WHERE ... ORDER BY RAND() LIMIT N query.
It means that for every row in table the RAND() function will be executed, then the whole table will be sorted according to value of this function and then first N...
Why does “_” (underscore) match “-” (hyphen)?
...u want to use the underscore in like as a literal, you have to escape it:
select * from a where name like '%taz\_manual%.pdf%';
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Difference: std::runtime_error vs std::exception()
... not standard. The runtime_error class has a constructor taking arguments (char*) on both platforms, Windows and Linux. To be portable, better use runtime_error.
(And remember, just because a specification of your project says your code does not have to run on Linux, it does not mean it does never ...
What do Clustered and Non clustered index actually mean?
...CLARE @C1 AS CURSOR,
@X AS INT
SET @C1 = CURSOR FAST_FORWARD
FOR SELECT number
FROM master..spt_values
WHERE type = 'P'
AND number BETWEEN 1 AND 100
ORDER BY CRYPT_GEN_RANDOM(4)
OPEN @C1;
FETCH NEXT FROM @C1 INTO @X;
WHILE @@FETCH_STATUS = 0
BEGIN
INSE...