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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 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 ...
How do I fix the Visual Studio compile error, “mismatch between processor architecture”?
... item.
Find your project in the list, under Platform it will say "Any CPU"
Select the "Any CPU" option from the drop down and then select <New..>
From that dialog, select x86 from the "New Platform" drop down and make sure "Any CPU" is selected in the "Copy settings from" drop down.
Hit OK
You...
JQuery: detect change in input field [duplicate]
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});
If you use the change handler, this will only fire after the user deselects the input box, which may not be what you want.
There is an example of both here: http://jsfiddle.net/6bSX6/
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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 device does not show up in adb list [closed]
... Android Nougat: Settings -> Developer options -> Networking -> Select USB Configuration. Changing it to MTP worked for me.
– sffc
Sep 5 '17 at 1:54
6
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COUNT DISTINCT with CONDITIONS
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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...
sqlalchemy IS NOT NULL select
How can I add the filter as in SQL to select values that are NOT NULL from a certain column ?
3 Answers
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Computed / calculated / virtual / derived columns in PostgreSQL
...y as column?
The expression (looking like a column) is not included in a SELECT * FROM tbl, though. You always have to list it explicitly.
Can also be supported with a matching expression index - provided the function is IMMUTABLE. Like:
CREATE FUNCTION col(tbl) ... AS ... -- your computed expr...
JPA eager fetch does not join
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JPA doesn't provide any specification on mapping annotations to select fetch strategy. In general, related entities can be fetched in any one of the ways given below
SELECT => one query for root entities + one query for related mapped entity/collection of each root entity = (n+1) que...