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Concatenate multiple result rows of one column into one, group by another column [duplicate]
...r):
SELECT movie, string_agg(actor, ', ') AS actor_list
FROM tbl
GROUP BY 1;
The 1 in GROUP BY 1 is a positional reference and a shortcut for GROUP BY movie in this case.
string_agg() expects data type text as input. Other types need to be cast explicitly (actor::text) - unless an implicit ca...
In SQL, how can you “group by” in ranges?
...0 and 19 then '10-19'
else '20-99' end as range
from scores) t
group by t.range
or
select t.range as [score range], count(*) as [number of occurrences]
from (
select user_id,
case when score >= 0 and score< 10 then '0-9'
when score >= 10 and score< 20 then ...
Row Offset in SQL Server
...
SELECT col1, col2
FROM (
SELECT col1, col2, ROW_NUMBER() OVER (ORDER BY ID) AS RowNum
FROM MyTable
) AS MyDerivedTable
WHERE MyDerivedTable.RowNum BETWEEN @startRow AND @endRow
SQL Server 2000
Efficiently Paging Through Large Result Sets in SQL Server 2000
A More Efficient Method for P...
Spring Data: “delete by” is supported?
...ing Spring JPA for database access. I am able to find examples such as findByName and countByName, for which I dont have to write any method implementation. I am hoping to find examples for delete a group of records based on some condition.
...
List passed by ref - help me explain this behaviour
...passing a reference to the list, but your aren't passing the list variable by reference - so when you call ChangeList the value of the variable (i.e. the reference - think "pointer") is copied - and changes to the value of the parameter inside ChangeList aren't seen by TestMethod.
try:
private voi...
How do shift operators work in Java? [duplicate]
...out.println(Integer.toBinaryString(2 << 11));
Shifts binary 2(10) by 11 times to the left. Hence: 1000000000000
System.out.println(Integer.toBinaryString(2 << 22));
Shifts binary 2(10) by 22 times to the left. Hence : 100000000000000000000000
System.out.println(Integer.toBinarySt...
Rails find_or_create_by more than one attribute?
There is a handy dynamic attribute in active-record called find_or_create_by:
5 Answers
...
C++ catch blocks - catch exception by value or reference? [duplicate]
I always catch exceptions by value. e.g
4 Answers
4
...
Using str_replace so that it only acts on the first match?
...ng to all the parameters, the real issue is that doing string manipulation by numbers is just tricky sometimes - you have to be careful to pass the right variable/offset to functions. I'd actually go so far as to say that the above code is the most straightforward, and to me, logical, approach.
...
Correct file permissions for WordPress [closed]
... to Hardening WordPress all files except for wp-content should be writable by your user account only. wp-content must be writable by www-data too.
chown <username>:<username> -R * # Let your useraccount be owner
chown www-data:www-data wp-content # Let apache be owner of wp-content
M...