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What are the differences between poll and select?
I am referring to the POSIX standard select and poll system C API calls.
3 Answers
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Vim search and replace selected text
Let's say we have a text, and I enter visual mode and select some text. How do I quickly do a search for the highlighted text and replace it with something else?
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What's a quick way to comment/uncomment lines in Vim?
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For those tasks I use most of the time block selection.
Put your cursor on the first # character, press CtrlV (or CtrlQ for gVim), and go down until the last commented line and press x, that will delete all the # characters vertically.
For commenting a block of text i...
How to create a MySQL hierarchical recursive query
... or self-joins.
MySQL 8+
with recursive cte (id, name, parent_id) as (
select id,
name,
parent_id
from products
where parent_id = 19
union all
select p.id,
p.name,
p.parent_id
from products p
inner join cte
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Difference between left join and right join in SQL Server [duplicate]
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Select * from Table1 left join Table2 ...
and
Select * from Table2 right join Table1 ...
are indeed completely interchangeable. Try however Table2 left join Table1 (or its identical pair, Table1 right join Table2) to see...
How to make HTML Text unselectable [duplicate]
I would like to add text to my webpage as a label and make it unselectable.
4 Answers
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Firefox ignores option selected=“selected”
If you change a dropdown and refresh the page, Firefox seems to ignore the selected attribute.
20 Answers
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How can I list ALL grants a user received?
...ust direct table grants (e.g., grants via roles, system privileges such as select any table, etc.), here are some additional queries:
System privileges for a user:
SELECT PRIVILEGE
FROM sys.dba_sys_privs
WHERE grantee = <theUser>
UNION
SELECT PRIVILEGE
FROM dba_role_privs rp JOIN role_...
MySQL: Fastest way to count number of rows
...s.
The solution is SQL_CALC_FOUND_ROWS. This is usually used when you are selecting rows but still need to know the total row count (for example, for paging).
When you select data rows, just append the SQL_CALC_FOUND_ROWS keyword after SELECT:
SELECT SQL_CALC_FOUND_ROWS [needed fields or *] FROM t...
Can someone explain collection_select to me in clear, simple terms?
I am going through the Rails API docs for collection_select and they are god-awful.
2 Answers
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