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Which data type for latitude and longitude?
...e using gist (geog);
and then request, say, 5 closest to a given point:
select *
from your_table
order by geog <-> 'SRID=4326;POINT(lon lat)'
limit 5;
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...
Boolean vs boolean in Java
...e (bar)?1:0 illustrates that bar (boolean) cannot be implicitly converted (casted) into an int. I am bringing this up not to illustrate the details of implementation behind JVM, but to point out that in terms of low level considerations (as memory size) one does have to prefer values over type safet...
How to convert an array to object in PHP?
...
In the simplest case, it's probably sufficient to "cast" the array as an object:
$object = (object) $array;
Another option would be to instantiate a standard class as a variable, and loop through your array while re-assigning the values:
$object = new stdClass();
foreach ...
Postgres: SQL to list table foreign keys
...
You can do this via the information_schema tables. For example:
SELECT
tc.table_schema,
tc.constraint_name,
tc.table_name,
kcu.column_name,
ccu.table_schema AS foreign_table_schema,
ccu.table_name AS foreign_table_name,
ccu.column_name AS foreign_column_nam...
Entity Framework: There is already an open DataReader associated with this Command
...al commands executed on single connection (or single command with multiple selects) while next DataReader is executed before first one has completed the reading. The only way to avoid the exception is to allow multiple nested DataReaders = turn on MultipleActiveResultSets. Another scenario when this...
What's the hardest or most misunderstood aspect of LINQ? [closed]
...string> { "Bob", "Alice", "Trent" };
var results = from s in items select s;
Console.WriteLine("Before add:");
foreach (var result in results)
{
Console.WriteLine(result);
}
items.Add("Mallory");
//
// Enumerating the results again will return the new ...
Easily measure elapsed time
...);
std::cout << "Time difference = " << std::chrono::duration_cast<std::chrono::microseconds>(end - begin).count() << "[µs]" << std::endl;
std::cout << "Time difference = " << std::chrono::duration_cast<std::chrono::nanoseconds> (end - begin).count()...
tinyxml XML解析库下载（tinyxml2.h 和 tinyxml2.cpp） - 源码下载 - 清泛...
...InternedStr( const char* str ) {
Reset();
_start = const_cast<char*>(str);
}
void SetStr( const char* str, int flags=0 );
char* ParseText( char* in, const char* endTag, int strFlags );
char* ParseName( char* in );
private:
void Reset();
void Col...
Java's L number (long) specification
...umed to be a double.
In all other cases (byte, short, char), you need the cast as there is no specific suffix.
The Java spec allows both upper and lower case suffixes, but the upper case version for longs is preferred, as the upper case L is less easy to confuse with a numeral 1 than the lower cas...
convert an enum to another type of enum
...), value.ToString());
If you mean by numeric value, you can usually just cast:
Enum2 value2 = (Enum2)value;
(with the cast, you might want to use Enum.IsDefined to check for valid values, though)
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