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Postgresql GROUP_CONCAT equivalent?
...
This is probably a good starting point (version 8.4+ only):
SELECT id_field, array_agg(value_field1), array_agg(value_field2)
FROM data_table
GROUP BY id_field
array_agg returns an array, but you can CAST that to text and edit as needed (see clarifications, below).
Prior to version...
what is the difference between GROUP BY and ORDER BY in sql
... SUM, COUNT, AVG, etc).
TABLE:
ID NAME
1 Peter
2 John
3 Greg
4 Peter
SELECT *
FROM TABLE
ORDER BY NAME
=
3 Greg
2 John
1 Peter
4 Peter
SELECT Count(ID), NAME
FROM TABLE
GROUP BY NAME
=
1 Greg
1 John
2 Peter
SELECT NAME
FROM TABLE
GROUP BY NAME
HAVING Count(ID) > 1
=
Peter
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how to emulate “insert ignore” and “on duplicate key update” (sql merge) with postgresql?
... two queries, one for INSERT and one for UPDATE (as an appropriate join/subselect of course - no need to write your main filter twice)
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Read error response body in Java
...bufferedReader.read()) != -1) {
sb.append((char) cp);
}
bufferedReader.close();
}
in.close();
} else {
/* error fro...
PostgreSQL query to return results as a comma separated list
Let say you have a SELECT id from table query (the real case is a complex query) that does return you several results.
5 ...
Counting the number of option tags in a select tag in jQuery
How do I count the number of <option> s in a <select> DOM element using jQuery?
8 Answers
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Email validation using jQuery
...l could be written in better way. None part of domain can start with other char than [a-z0-9] (case insensitive). Also, valid e-mail (and domain) has some len limit, which is also not tested.
– tomis
Jul 5 '13 at 8:42
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What are some uses of template template parameters?
....2, 3.3, 4.4 };
std::cout << vf << '\n';
std::list<char> lc { 'a', 'b', 'c', 'd' };
std::cout << lc << '\n';
std::deque<int> di { 1, 2, 3, 4 };
std::cout << di << '\n';
return 0;
}
Output
std::ostream &operator<<...
How to negate specific word in regex? [duplicate]
I know that I can negate group of chars as in [^bar] but I need a regular expression where negation applies to the specific word - so in my example how do I negate an actual bar , and not "any chars in bar"?
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Sql Server equivalent of a COUNTIF aggregate function
...u could use a SUM (not COUNT!) combined with a CASE statement, like this:
SELECT SUM(CASE WHEN myColumn=1 THEN 1 ELSE 0 END)
FROM AD_CurrentView
Note: in my own test NULLs were not an issue, though this can be environment dependent. You could handle nulls such as:
SELECT SUM(CASE WHEN ISNULL(myC...