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How to concatenate strings of a string field in a PostgreSQL 'group by' query?
...at the question asked for, even letting you specify the delimiter string:
SELECT company_id, string_agg(employee, ', ')
FROM mytable
GROUP BY company_id;
Postgres 9.0 also added the ability to specify an ORDER BY clause in any aggregate expression; otherwise, the order is undefined. So you can no...
An explicit value for the identity column in table can only be specified when a column list is used
...tead of
SET IDENTITY_INSERT archive_table ON;
INSERT INTO archive_table
SELECT *
FROM source_table;
SET IDENTITY_INSERT archive_table OFF;
you need to write
SET IDENTITY_INSERT archive_table ON;
INSERT INTO archive_table (field1, field2, ...)
SELECT field1, field2, ...
FROM source_table;...
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"]]
...
MySQL, Check if a column exists in a table with SQL
...query and I think it needs a small alteration to get it working properly.
SELECT *
FROM information_schema.COLUMNS
WHERE
TABLE_SCHEMA = 'db_name'
AND TABLE_NAME = 'table_name'
AND COLUMN_NAME = 'column_name'
That worked for me.
Thanks!
...
How do I get IntelliJ IDEA to display directories?
...correctly. Make sure the "Content Root" is correct.
Click on the project
Select "File"->"Project Structure"
Select "modules" from the left column, and select a module.
On the sources tab you will see the current "Content Root" along with a button to add a new content root.
Make sure that con...
App Inventor 2 项目合并工具 AIMerge · App Inventor 2 中文网
... CountDownScreen1 project, then clicking on the “Project” dropdown and selecting “Export selected project (.aia) to my computer”. Figure 4 shows how to select a project and where to click to download the project.
Figure 4: Steps to download the CountDownScreen1 project
Develope...
How can I selectively merge or pick changes from another branch in Git?
... git rebase -i to get the original commit to edit, then git reset HEAD^ to selectively revert changes, then git commit to commit that bit as a new commit in the history.
There is another nice method here in Red Hat Magazine, where they use git add --patch or possibly git add --interactive which all...
IIS - 401.3 - Unauthorized
... configuration of your site, modify the "Anonymous authentication" line by selecting "Identity of the application pool" instead of "Specific user".
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Get selected element's outer HTML
I'm trying to get the HTML of a selected object with jQuery. I am aware of the .html() function; the issue is that I need the HTML including the selected object (a table row in this case, where .html() only returns the cells inside the row).
...
Hide options in a select list using jQuery
...ave an object with key/value pairs of options I want to hide/remove from a select list.
Neither of the following option selectors work. What am I missing?
...