大约有 47,000 项符合查询结果（耗时：0.0297秒） [XML]
How to include “zero” / “0” results in COUNT aggregate?
...n outer join for this (and you need to use person as the "driving" table)
SELECT person.person_id, COUNT(appointment.person_id) AS "number_of_appointments"
FROM person
LEFT JOIN appointment ON person.person_id = appointment.person_id
GROUP BY person.person_id;
The reason why this is working, i...
Eclipse git checkout (aka, revert)
...ing" view, right click the deleted file in the "Unstaged Changes" list and select "Replace with HEAD Revision"
– Vlasta Dolejs
Sep 5 '17 at 8:03
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How do I convert an interval into a number of hours with postgres?
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Probably the easiest way is:
SELECT EXTRACT(epoch FROM my_interval)/3600
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How can I know which radio button is selected via jQuery?
I have two radio buttons and want to post the value of the selected one.
How can I get the value with jQuery?
37 Answers
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How to get a list of MySQL views?
...to leave the "IN database_name" away if you look for view in the currently selected DB.
– kraftb
Jun 2 '15 at 17:11
To...
Mac SQLite editor [closed]
... info.plist and setting it to YES
Running the app on a device
Open iTunes
Select the device
Select the "Apps" tab
Scroll down to the "File Sharing" section and select the app
The .sqlite file should appear in the right hand pane - select it and "Save to..."
Once it's saved open it up in your favour...
The multi-part identifier could not be bound
...tion is specified in the WHERE clause).
Here's an outline of your query:
SELECT
…
FROM a, b LEFT JOIN dkcd ON …
WHERE …
You are probably expecting it to behave like this:
SELECT
…
FROM (a, b) LEFT JOIN dkcd ON …
WHERE …
that is, the combination of tables a and b is joined with...
Extracting specific columns from a data frame
...r package, if your data.frame is called df1:
library(dplyr)
df1 %>%
select(A, B, E)
This can also be written without the %>% pipe as:
select(df1, A, B, E)
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How do you remove all the options of a select box and then add one option and select it with jQuery?
Using core jQuery, how do you remove all the options of a select box, then add one option and select it?
24 Answers
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Is it possible to select the last n items with nth-child?
Using a standard list, I'm trying to select the last 2 list items. I've various permutations of An+B but nothing seems to select the last 2:
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