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JSON.NET Error Self referencing loop detected for type
...ceLoopHandling = ReferenceLoopHandling.Ignore,
}, ArrayPool<char>.Shared));
});
}
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Which, if any, C++ compilers do tail-recursion optimization?
...t for program correctness.
#include <stdio.h>
static int atoi(const char *str, int n)
{
if (str == 0 || *str == 0)
return n;
return atoi(str+1, n*10 + *str-'0');
}
int main(int argc, char **argv)
{
for (int i = 1; i != argc; ++i)
printf("%s -> %d\n", argv[i], at...
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 do I check if a number is positive or negative in C#?
...
This is the industry standard:
int is_negative(float num)
{
char *p = (char*) malloc(20);
sprintf(p, "%f", num);
return p[0] == '-';
}
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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...
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...
Finding duplicate values in MySQL
...
Do a SELECT with a GROUP BY clause. Let's say name is the column you want to find duplicates in:
SELECT name, COUNT(*) c FROM table GROUP BY name HAVING c > 1;
This will return a result with the name value in the first colum...
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...
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>
...
Random hash in Python
...question:
import random, string
def random_md5like_hash():
available_chars= string.hexdigits[:16]
return ''.join(
random.choice(available_chars)
for dummy in xrange(32))
I'm not saying it's faster or preferable to any other answer; just that it's another approach :)
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