大约有 40,000 项符合查询结果(耗时:0.0689秒) [XML]
Find index of a value in an array
... return -1;
}
And you can use LINQ as well:
int keyIndex = words
.Select((v, i) => new {Word = v, Index = i})
.FirstOrDefault(x => x.Word.IsKey)?.Index ?? -1;
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sql “LIKE” equivalent in django query
... = table.objects.filter(string__contains='pattern')
The SQL equivalent is
SELECT ... WHERE string LIKE '%pattern%';
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MIN/MAX vs ORDER BY and LIMIT
...oks like MIN() is able to simply pluck the smallest value from the index ('Select tables optimized away' and 'NULL' rows) whereas the SORT and LIMIT still needs needs to do an ordered traversal of the index (106,000 rows). The actual performance impact is probably negligible.
It looks like MIN() i...
Filter by property
...ral models, and this routine should work for all models. And it does:
def selectByProperties(modelType, specify):
clause = "SELECT * from %s" % modelType._meta.db_table
if len(specify) > 0:
clause += " WHERE "
for field, eqvalue in specify.items():
clause += ...
What is syntax for selector in CSS for next element?
...
This is called the adjacent sibling selector, and it is represented by a plus sign...
h1.hc-reform + p {
clear:both;
}
Note: this is not supported in IE6 or older.
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Create an array or List of all dates between two dates [duplicate]
...
LINQ:
Enumerable.Range(0, 1 + end.Subtract(start).Days)
.Select(offset => start.AddDays(offset))
.ToArray();
For loop:
var dates = new List<DateTime>();
for (var dt = start; dt <= end; dt = dt.AddDays(1))
{
dates.Add(dt);
}
EDIT:
As for padding value...
What is `related_name` used for in Django?
... use for prefetch data for Many to many and many to one relationship data.
select_related is to select data from a single value relationship. Both of these are used to fetch data from their relationships from a model. For example, you build a model and a model that has a relationship with other mode...
What CSS selector can be used to select the first div within another div
...
Can you tell me how to select all div except first/last div?
– Tân
Jul 5 '16 at 9:17
5
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Real differences between “java -server” and “java -client”?
...ient option is ignored for many years.
See Windows java command:
-client
Selects the Java HotSpot Client VM.
A 64-bit capable JDK currently ignores this option and instead uses the Java Hotspot Server VM.
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How to make a JTable non-editable
...(int,int) which takes rowIndex and coulmnIndex as parameters. The user can selectively enable/disable editing for a particular row/column by overriding "isCellEditable" method or can use the default implementation to disable editing for all cells.
– sateesh
Jan...