大约有 46,000 项符合查询结果（耗时：0.0382秒） [XML]
What's the difference(s) between .ToList(), .AsEnumerable(), AsQueryable()?
...al joins where a certain Column that is calculated on the view for example concat(t1.colA, t2.colB, t2.colC) as MyVeryNeetColumn (i know its a stupid example, but could be anything). When you do a Where on that column in it will have horrible times because the db needs to calculate all vals to perfo...
Lua简明教程 - 脚本技术 - 清泛IT论坛，有思想、有深度
...; 对应表达式 -a
__concat(a, b) 对应表达式 a .. b
__len(a)  ...
Questions every good .NET developer should be able to answer? [closed]
...te where people are trying to roll their own version of Union Distinct and Concat for collections because they don't understand LINQ.
– Evan Plaice
Jun 19 '10 at 1:04
...
Standard alternative to GCC's ##__VA_ARGS__ trick?
...election of either REST_HELPER_ONE() or REST_HELPER_TWOORMORE() is done by concatenating REST_HELPER_ with the expansion of NUM(__VA_ARGS__) in REST_HELPER2(). Note that the purpose of REST_HELPER() is to ensure that NUM(__VA_ARGS__) is fully expanded before being concatenated with REST_HELPER_.
E...
Fastest way to flatten / un-flatten nested JSON objects
... Object.keys(obj).forEach(key => {
this.flatten(obj[key], prefix.concat(key), current)
})
} else {
current[prefix.join('.')] = obj
}
return current
}
Features and/or caveats
It only accepts JSON objects. So if you pass something like {a: () => {}} you might not get wh...
Quickest way to convert a base 10 number to any base in .NET?
...ike that (note that this surely can be made faster by replacing the string concatenation):
class Program
{
static void Main(string[] args)
{
// convert to binary
string binary = IntToString(42, new char[] { '0', '1' });
// convert to hexadecimal
string hex =...
What is the most efficient/elegant way to parse a flat table into a tree?
...r_id = 1
ORDER BY f.name;
Re comment from @Nate:
SELECT f.name, GROUP_CONCAT(b.ancestor_id order by b.path_length desc) AS breadcrumbs
FROM FlatTable f
JOIN ClosureTable a ON (f.id = a.descendant_id)
JOIN ClosureTable b ON (b.descendant_id = a.descendant_id)
WHERE a.ancestor_id = 1
GROUP BY...
What is the difference between a string and a byte string?
... False even when they contain exactly the same characters.
>>> # concatenation
>>> b'hi' + b'bye' # this is possible
b'hibye'
>>> 'hi' + 'bye' # this is also possible
'hibye'
>>> b'hi' + 'bye' # this will fail
Traceback (most recent call last):
File "<stdin&...
Is there a MySQL option/feature to track history of changes to records?
...ary_key_column as 'row id',
IF(t1.a_column = t2.a_column, t1.a_column, CONCAT(t1.a_column, " to ", t2.a_column)) as a_column
FROM MyDB.data_history as t1 INNER join MyDB.data_history as t2 on t1.primary_key_column = t2.primary_key_column
WHERE (t1.revision = 1 AND t2.revision = 1) OR t2.r...
how to draw smooth curve through N points using javascript HTML5 canvas?
... for (var i = 0; i < pts.length - 2; i += 1) {
cps = cps.concat(ctlpts(pts[2*i], pts[2*i+1],
pts[2*i+2], pts[2*i+3],
pts[2*i+4], pts[2*i+5]));
}
if ($("showControlLines").check...