大约有 48,000 项符合查询结果（耗时：0.0264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...
Viewing complete strings while debugging in Eclipse
...ck on Details pane (the section where the string content is displayed) and select "Max Length..." popup menu. The same length applies to expression inspector popup and few other places.
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Hidden Features of Xcode 4
... View > Utilities > Code Snippet Library. To add a new code snippet, select some text in the editor view and drag it into the snippet library. You can either drag a snippet out and drop it in your code to use it, or, much more conveniently, assign a completion shortcut to it.
When you type i...
How to automatically install Emacs packages by specifying a list of package names?
...nsure keyword to install packages automatically. This also sets up package-selected-packages if you need to access the package list through customize or programatically.
– Nick McCurdy
Apr 21 '17 at 22:16
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How to stop a program running under Eclipse?
...r. For this you can open up the devices window (in the debug perspective), select the process and then press the stop button on the same window.
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Android Studio: Add jar as library?
.... Click the + sign above the panel second from the left -> Java
4.4. Select your local jar and add it to the project.
You may need to run the above ./gradlew command one more time
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How to do SELECT COUNT(*) GROUP BY and ORDER BY in Django?
...lvaro has answered the Django's direct equivalent for GROUP BY statement:
SELECT actor, COUNT(*) AS total
FROM Transaction
GROUP BY actor
is through the use of values() and annotate() methods as follows:
Transaction.objects.values('actor').annotate(total=Count('actor')).order_by()
However ...
Selecting the last value of a column
...
Another good resource is the selected answer at productforums.google.com/forum/#!topic/docs/p3t3feg7Jic which shows how to get the first, last, or nth row in a FILTER()ed range, similar to @Geta's answer.
– Aaron Blenkush
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Is SQL syntax case sensitive?
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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...
How to find largest objects in a SQL Server database?
...quite a bit understanding and determining the size of indices and tables:
SELECT
t.name AS TableName,
i.name as indexName,
sum(p.rows) as RowCounts,
sum(a.total_pages) as TotalPages,
sum(a.used_pages) as UsedPages,
sum(a.data_pages) as DataPages,
(sum(a.total_pages) *...