大约有 48,000 项符合查询结果（耗时：0.0281秒） [XML]
SQL RANK() versus ROW_NUMBER()
...he first 3 rows are tied when ordered by ID)
WITH T(StyleID, ID)
AS (SELECT 1,1 UNION ALL
SELECT 1,1 UNION ALL
SELECT 1,1 UNION ALL
SELECT 1,2)
SELECT *,
RANK() OVER(PARTITION BY StyleID ORDER BY ID) AS 'RANK',
ROW_NUMBER() OVER(PARTITION BY Style...
MySQL Results as comma separated list
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You can use GROUP_CONCAT to perform that, e.g. something like
SELECT p.id, p.name, GROUP_CONCAT(s.name) AS site_list
FROM sites s
INNER JOIN publications p ON(s.id = p.site_id)
GROUP BY p.id, p.name;
share
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Reshaping data.frame from wide to long format
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Here is another example showing the use of gather from tidyr. You can select the columns to gather either by removing them individually (as I do here), or by including the years you want explicitly.
Note that, to handle the commas (and X's added if check.names = FALSE is not set), I am also us...
Extract a dplyr tbl column as a vector
...2 3.62 3.54 4.11
A nice way to do this in v0.2 of dplyr:
iris2 %>% select(Species) %>% collect %>% .[[5]]
Or if you prefer:
iris2 %>% select(Species) %>% collect %>% .[["Species"]]
Or if your table isn't too big, simply...
iris2 %>% collect %>% .[["Species"]]
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Why Android Studio says “Waiting For Debugger” if am NOT debugging?
...e. Just go to "Android device"->"Settings"->"Developer Options"->"Select app to be debugged". It will likely be pointing to your application. Just select the option and then select "None".
Note: As mentioned, even if "None" is already selected, re-selecting "None" appears to correct the pr...
Eclipse copy/paste entire line keyboard shortcut
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Ctrl-Alt-Down: copies current line or selected lines to below
Ctrl-Alt-Up:: copies current line or selected lines to above
Ctrl-Shift-L: brings up a List of shortcut keys
See Windows/Preference->General->Keys.
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Visual Studio - Shortcut to Navigate to Solution Explorer
Is there a keyboard shortcut in Visual Studio (aside from CTRL + TAB and selection) that would take me from inside a document directly into the solution explorer? I don't want to customize any shortcuts or change any default behavior.
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LINQ: When to use SingleOrDefault vs. FirstOrDefault() with filtering criteria
... When I ran a SingleOrDefault through LinqPad and VS, I never got SELECT TOP 2, with FirstOrDefault I was able to get SELECT TOP 1, but as far as I can tell you do not get SELECT TOP 2.
– Jamie R Rytlewski
Dec 22 '11 at 15:04
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Set selected radio from radio group with a value
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With the help of the attribute selector you can select the input element with the corresponding value. Then you have to set the attribute explicitly, using .attr:
var value = 5;
$("input[name=mygroup][value=" + value + "]").attr('checked', 'checked');
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Eclipse: How do you change the highlight color of the currently selected method/expression?
...from the Annotation types list.
Then, be sure that Text as highlighted is selected, then choose the desired color.
And, a picture is worth a thousand words...
(source: coobird.net)
(source: coobird.net)
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