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MySQL Error 1215: Cannot add foreign key constraint
...
It could also be that the character set is different. I hade this problem where one column had the utf8 character set while the other had latin1. Easily fixed with ALTER TABLE Table CHARACTER SET = utf8 ; and ALTER TABLE Device CHANGE COLUMN ID ID CHA...
When should the volatile keyword be used in C#?
...t (40203Ch)]
00401045 call dword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (402038h)]
}
0040104B xor eax,eax
0040104D pop ecx
0040104E ret
Looking at the output, the compiler has decided to use the ecx re...
What's faster, SELECT DISTINCT or GROUP BY in MySQL?
...'t, then use DISTINCT.
GROUP BY in MySQL sorts results. You can even do:
SELECT u.profession FROM users u GROUP BY u.profession DESC
and get your professions sorted in DESC order.
DISTINCT creates a temporary table and uses it for storing duplicates. GROUP BY does the same, but sortes the disti...
How to get 0-padded binary representation of an integer in java?
...ormatter, I would advise you to either use String.replace to replace space character with zeros, as in:
String.format("%16s", Integer.toBinaryString(1)).replace(" ", "0")
Or implement your own logic to convert integers to binary representation with added left padding somewhere along the lines giv...
Resolve build errors due to circular dependency amongst classes
...;<endl;
}
//main.cpp
#include "A.h"
#include "B.h"
int main(int argc, char* argv[])
{
A a(10);
B b(3.14);
a.Print();
a.SetB(&b);
b.Print();
b.SetA(&a);
return 0;
}
share
|
...
Find all tables containing column with specified name - MS SQL Server
...
Search Tables:
SELECT c.name AS 'ColumnName'
,t.name AS 'TableName'
FROM sys.columns c
JOIN sys.tables t ON c.object_id = t.object_id
WHERE c.name LIKE '%MyName%'
ORDER BY TableName
,C...
What is the fastest/most efficient way to find the highest set bit (msb) in an integer in C?
...ruction.)
Example code for gcc:
#include <iostream>
int main (int,char**)
{
int n=1;
for (;;++n) {
int msb;
asm("bsrl %1,%0" : "=r"(msb) : "r"(n));
std::cout << n << " : " << msb << std::endl;
}
return 0;
}
See also this inline assembler tutoria...
How to have a default option in Angular.js select box
...
You can simply use ng-init like this
<select ng-init="somethingHere = options[0]"
ng-model="somethingHere"
ng-options="option.name for option in options">
</select>
...
Mysql order by specific ID values
... use ORDER BY and FIELD function.
See http://lists.mysql.com/mysql/209784
SELECT * FROM table ORDER BY FIELD(ID,1,5,4,3)
It uses Field() function, Which "Returns the index (position) of str in the str1, str2, str3, ... list. Returns 0 if str is not found" according to the documentation. So actual...
What is the difference between JOIN and UNION?
...t -- completely different operations. Trivial example of UNION:
mysql> SELECT 23 AS bah
-> UNION
-> SELECT 45 AS bah;
+-----+
| bah |
+-----+
| 23 |
| 45 |
+-----+
2 rows in set (0.00 sec)
similary trivial example of JOIN:
mysql> SELECT * FROM
-> (SELECT 23 AS bah...