大约有 44,000 项符合查询结果（耗时：0.0471秒） [XML]
Filter dataframe rows if value in column is in a set list of values [duplicate]
...id 7
9 1980-01-10 9 Jones 4
There are multiple ways of selecting or slicing the data.
Using .isin
The most obvious is the .isin feature. You can create a mask that gives you a series of True/False statements, which can be applied to a dataframe like this:
mask = df['STK_ID'].isin...
Preserving order with LINQ
...p a source element by index to a result element
AsEnumerable
Cast
Concat
Select
ToArray
ToList
Preserves Order. Elements are filtered or added, but not re-ordered.
Distinct
Except
Intersect
OfType
Prepend (new in .net 4.7.1)
Skip
SkipWhile
Take
TakeWhile
Where
Zip (new in .net 4)
Destroys O...
Fastest Way to Find Distance Between Two Lat/Long Points
...ate a SPATIAL index on these points
Use MBRContains() to find the values:
SELECT *
FROM table
WHERE MBRContains(LineFromText(CONCAT(
'('
, @lon + 10 / ( 111.1 / cos(RADIANS(@lon)))
, ' '
, @lat + 10 / 111.1
, ','
, @lon - 10 / ( 111.1 / cos(RADI...
When to use std::forward to forward arguments?
...tempted to conclude), but a universal reference*. Universal references are characterized by a very restricted form (just T&&, without const or similar qualifiers) and by type deduction - the type T will be deduced when f is invoked. In a nutshell, universal references correspond to rvalue r...
How to check in Javascript if one element is contained within another
...arentNode)&&c!==p);
return !!c;
}
..or as one-liner (just 64 chars!):
function childOf(c,p){while((c=c.parentNode)&&c!==p);return !!c}
and jsfiddle here.
Usage:
childOf(child, parent) returns boolean true|false.
Explanation:
while evaluates as long as the while-condition...
Distinct in Linq based on only one field of the table
...
Try this:
table1.GroupBy(x => x.Text).Select(x => x.FirstOrDefault());
This will group the table by Text and use the first row from each groups resulting in rows where Text is distinct.
...
How to generate serial version UID in Intellij
...
very nice, very easy to install. you can install that from plugins menu, select install from disk, select the jar file you unpacked in the lib folder. restart, control + ins, and it pops up to generate serial UID from menu. love it. :-)
...
What is the best way to conditionally apply a class?
...ul with an li for each element and a property on the controller called selectedIndex . What would be the best way to add a class to the li with the index selectedIndex in AngularJS?
...
What is this operator in MySQL?
...d <> both give UNKNOWN with NULL on either side of the expression.)
SELECT *
FROM table
WHERE YourColumn IS NOT NULL;
can also negate the null safe equality operator but this is not standard SQL.
SELECT *
FROM table
WHERE NOT (YourColumn <=> NULL);
...
How can I select the first day of a month in SQL?
I just need to select the first day of the month of a given datetime variable.
30 Answers
...