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How do I remove duplicate items from an array in Perl?
...een; grep !$seen{$_}++, @_ } is a better implementation since it preserves order at no cost. Or even better, use the one from List::MoreUtils.
– ikegami
Nov 6 '12 at 18:51
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oracle top 替代方案 - 数据库(内核) - 清泛网 - 专注C/C++及内核技术
...案由于Oracle不支持select top 语句，所以在Oracle中经常是用order by 跟 rownum的组合来实现select top n的查询。select * from (...由于Oracle不支持select top 语句，所以在Oracle中经常是用order by 跟 rownum 的组合来实现select top n的查询。
select * f...
MySQL ON vs USING?
...ces one output column for each
of the listed column pairs (in the listed order), followed by any
remaining columns from T1, followed by any remaining columns from T2.
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How to correctly close a feature branch in Mercurial?
...ant to merge results back to the default branch and close feature-x in order to get rid of it in the output of hg branches .
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What is a magic number, and why is it bad? [closed]
... update.
For example, let's say you have a Page that displays the last 50 Orders in a "Your Orders" Overview Page. 50 is the Magic Number here, because it's not set through standard or convention, it's a number that you made up for reasons outlined in the spec.
Now, what you do is you have the 50 ...
What are Aggregates and PODs and how/why are they special?
...f the array elements we will initialize the non-static data members in the order of their appearance in the class definition (they are all public by definition). If there are fewer initializers than members, the rest are value-initialized. If it is impossible to value-initialize one of the members w...
Authoritative position of duplicate HTTP GET query keys
... of the question, there is also the option of ['rails', 'ruby'] (different order).
– Thilo
Nov 18 '09 at 0:48
2
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Is Java “pass-by-reference” or “pass-by-value”?
...e get to the Java implementation:
Values go on and off the stack in a nice orderly fashion, like a stack of plates at a cafeteria.
Memory in the heap (also known as dynamic memory) is haphazard and disorganized. The JVM just finds space wherever it can, and frees it up as the variables that use it a...
How to make a query with group_concat in sql server [duplicate]
...AX)'), 1, 1, '')
FROM dbo.tblmask m
JOIN dbo.school s ON s.ID = m.schoolid
ORDER BY m.maskname
Additional information:
String Aggregation in the World of SQL Server
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How to select the rows with maximum values in each group with dplyr? [duplicate]
...g of A and B values.
group_by( A, B) %>%
# Sort rows in descending order by "value" column.
arrange( desc(value) ) %>%
# Pick the top 1 value
slice(1) %>%
# Remember to ungroup in case you want to do further work without grouping.
ungroup()
# Answering an extension of the ...