大约有 48,000 项符合查询结果（耗时：0.0691秒） [XML]
COUNT DISTINCT with CONDITIONS
...
You can try this:
select
count(distinct tag) as tag_count,
count(distinct (case when entryId > 0 then tag end)) as positive_tag_count
from
your_table_name;
The first count(distinct...) is easy.
The second one, looks somewhat complex...
Is SQL syntax case sensitive?
...
The SQL Keywords are case-insensitive (SELECT, FROM, WHERE, etc), but are often written in all caps. However in some setups table and column names are case-sensitive. MySQL has a configuration option to enable/disable it. Usually case-sensitive table and column na...
Map and Reduce in .NET
...ons. C# 3.5 and Linq already has it albeit under different names.
Map is Select:
Enumerable.Range(1, 10).Select(x => x + 2);
Reduce is Aggregate:
Enumerable.Range(1, 10).Aggregate(0, (acc, x) => acc + x);
Filter is Where:
Enumerable.Range(1, 10).Where(x => x % 2 == 0);
https://www...
adding and removing classes in angularJs using ng-click
...s code actuali change class for all div, how I can apply class only to the selected clicked item
– xzegga
Apr 24 '14 at 4:44
...
Export query result to .csv file in SQL Server 2008
...opy the query.
In Object Explorer right-click on the database in question.
Select "Tasks" >> "Export Data..."
Configure your datasource, and click "Next".
Choose "Flat File" or "Microsoft Excel" as destination.
Specify a file path.
If working with a flat file, configure as desired. If working ...
List comprehension in Ruby
..._ARRAY.map{|x| x % 2 == 0 ? x * 3 : nil}.compact
end
end
def test_select_map
1000.times do
TEST_ARRAY.select{|x| x % 2 == 0 }.map{|x| x * 3}
end
end
def test_inject
1000.times do
TEST_ARRAY.inject([]) {|all, x| all << x*3 if x % 2 == 0; all }
end
end...
Change Placeholder Text using jQuery
... Note for OP: Also note that the change event is hooked to the select box, not the text input. $('#serMemdd').change(function () {
– Benjam
Feb 10 '12 at 18:51
...
foreach with index [duplicate]
...
You can do the following
foreach (var it in someCollection.Select((x, i) => new { Value = x, Index = i }) )
{
if (it.Index > SomeNumber) //
}
This will create an anonymous type value for every entry in the collection. It will have two properties
Value: with the ori...
Android Gallery on Android 4.4 (KitKat) returns different URI for Intent.ACTION_GET_CONTENT
...tyForResult(Intent.createChooser(intent, getResources().getString(R.string.select_picture)),GALLERY_INTENT_CALLED);
} else {
Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType("image/jpeg");
startActivityForResult(int...
SQL how to make null values come last when sorting ascending
...
select MyDate
from MyTable
order by case when MyDate is null then 1 else 0 end, MyDate
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