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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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Oracle SQL: Update a table with data from another table
...his is called a correlated update
UPDATE table1 t1
SET (name, desc) = (SELECT t2.name, t2.desc
FROM table2 t2
WHERE t1.id = t2.id)
WHERE EXISTS (
SELECT 1
FROM table2 t2
WHERE t1.id = t2.id )
Assuming the join results in a key-pr...
What's faster, SELECT DISTINCT or GROUP BY in MySQL?
...'t, then use DISTINCT.
GROUP BY in MySQL sorts results. You can even do:
SELECT u.profession FROM users u GROUP BY u.profession DESC
and get your professions sorted in DESC order.
DISTINCT creates a temporary table and uses it for storing duplicates. GROUP BY does the same, but sortes the disti...
Convert special characters to HTML in Javascript
Does any one know how to convert special characters to HTML in Javascript ?
26 Answers
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postgresql: INSERT INTO … (SELECT * …)
...ostgres
CREATE TABLE tblA (id serial, time integer);
INSERT INTO tblA
SELECT id, time
FROM dblink('dbname=dbtest', 'SELECT id, time FROM tblB')
AS t(id integer, time integer)
WHERE time > 1000;
TABLE tblA;
id | time
----+------
1 | 5000
2 | 2000
(2 rows)
PostgreSQL has ...
Select text on input focus
I have a text input. When the input receives focus I want to select the text inside of the input.
10 Answers
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How do I use variables in Oracle SQL Developer?
... other stuff didn't work for me, but this did:
define value1 = 'sysdate'
SELECT &&value1 from dual;
Also it's the slickest way presented here, yet.
(If you omit the "define"-part you'll be prompted for that value)
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How to remove all whitespace from a string?
...paces before, after and in between
" \u2190 \u2192 ", # contains unicode chars
paste0( # varied whitespace
whitespace,
"x",
whitespace,
"y",
whitespace,
collapse = ""
),
NA # missing
)
## [1] " x y "
#...
jQuery count child elements
...
You can use .length with just a descendant selector, like this:
var count = $("#selected li").length;
If you have to use .children(), then it's like this:
var count = $("#selected ul").children().length;
You can test both versions here.
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The simplest way to comma-delimit a list?
....
The StringJoiner class.
Example:
// Util method for strings and other char sequences
List<String> strs = Arrays.asList("1", "2", "3");
String listStr1 = String.join(",", strs);
// For any type using streams and collectors
List<Object> objs = Arrays.asList(1, 2, 3);
String listStr2 ...