大约有 40,000 项符合查询结果（耗时：0.0194秒） [XML]
Filling a DataSet or DataTable from a LINQ query result set
...has a CopyToDataTable method:
IEnumerable<DataRow> query =
from order in orders.AsEnumerable()
where order.Field<DateTime>("OrderDate") > new DateTime(2001, 8, 1)
select order;
// Create a table from the query.
DataTable boundTable = query.CopyToDataTable<DataRow>(...
Converting an array of objects to ActiveRecord::Relation
...ECT .... WHERE `my_models`.id IN (2, 3, 4, 6, ....
Keep in mind that the ordering of the array will be lost - But since your objective is only to run a class method on the collection of these objects, I assume it won't be a problem.
...
Is it possible to GROUP BY multiple columns using MySQL?
...
Preference of left to right is applied to the ascending order of the groupings and not the column group preference. GROUP BY applies col1+col2. e.g. col1 = 1, 2, 1, 2 | col2 = 1, 2, 3, 2 and running GROUP BY col1,col2 would return 1,1|1,3|2,2 as opposed to 1,1|2,2 as suggested. Wh...
What is difference between Collection.stream().forEach() and Collection.forEach()?
...number of subtle differences that might be significant.
One issue is with ordering. With Stream.forEach, the order is undefined. It's unlikely to occur with sequential streams, still, it's within the specification for Stream.forEach to execute in some arbitrary order. This does occur frequently in ...
How does one reorder columns in a data frame?
...s keep all the rows, and the 1,2,3,4 refers to the columns.
To change the order as in the above question do df2[,c(1,3,2,4)]
If you want to output this file as a csv, do write.csv(df2, file="somedf.csv")
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How can I convert a dictionary into a list of tuples?
...or k, v in d.iteritems()]
[(1, 'a'), (3, 'c'), (2, 'b')]
It's not in the order you want, but dicts don't have any specific order anyway.1 Sort it or organize it as necessary.
See: items(), iteritems()
In Python 3.x, you would not use iteritems (which no longer exists), but instead use items, w...
SQL Server: SELECT only the rows with MAX(DATE)
...
If rownumber() over(...) is available for you ....
select OrderNO,
PartCode,
Quantity
from (select OrderNO,
PartCode,
Quantity,
row_number() over(partition by OrderNO order by DateEntered desc) as rn
from YourTable) as T
whe...
When to use DataContract and DataMember attributes?
...non-public properties or fields
without [DataMember], you cannot define an order of serialization (Order=) and the DCS will serialize all properties alphabetically
without [DataMember], you cannot define a different name for your property (Name=)
without [DataMember], you cannot define things like I...
Java: how to convert HashMap to array
...ray(); // returns an array of values
Edit
It should be noted that the ordering of both arrays may not be the same,
See oxbow_lakes answer for a better approach for iteration when the pair key/values are needed.
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Why use make over a shell script?
... other sort of tree analysis that determines what depends on what and what order to build the out-of-date things such that every prerequisite is built before every dependency, and only built once.
It's a language for declarative programming. New elements can be added without needing to merge them in...