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Create batches in linq
... int maxItems)
{
return items.Select((item, inx) => new { item, inx })
.GroupBy(x => x.inx / maxItems)
.Select(g => g.Select(x => x.item));
}
}
and the usage would be:
List<int> list = new L...
How do I format a number with commas in T-SQL?
...
In SQL Server 2012 and higher, this will format a number with commas:
select format([Number], 'N0')
You can also change 0 to the number of decimal places you want.
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A circular reference was detected while serializing an object of type 'SubSonic.Schema .DatabaseColu
...
I think maybe selecting the ones I want may work I think the circular reference is because in Event I have IQueryable<Category> which in turn will have a IQueryable<Event>
– Jon
Jul 20 '09...
What is PostgreSQL explain telling me exactly?
...ly 1 sentence of technical content: "• EXPLAIN works on any DML not just SELECT (ie UPDATE, DELETE, and INSERT)". My biggest misunderstanding is what "startup" time means, and that's not explained anywhere in these ~30 slides.
– Mark E. Haase
Feb 19 '16 at 15...
GridCtrl 控件FAQ - C/C++ - 清泛网 - 专注C/C++及内核技术
...能被选中（默认就是固定的不能被选）
m_Grid.SetFixedColumnSelection(FALSE);
m_Grid.SetFixedRowSelection(FALSE);
//设置控件是否允许隐藏行或者列
m_Grid.EnableColumnHide(FALSE);
m_Grid.EnableRowHide(FALSE);
//设置控件是否允许编辑
m_Grid.SetEditable(FA...
IN vs OR in the SQL WHERE Clause
...h are nearly instant. When the column is not indexed I got these results:
SELECT COUNT(*) FROM t_inner WHERE val IN (1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000);
1 row fetched in 0.0032 (1.2679 seconds)
SELECT COUNT(*) FROM t_inner WHERE val = 1000 OR val = 2000 OR val = 3000 OR val = 40...
MYSQL OR vs IN performance
...for future Googlers. Total count of returned results is 7264 out of 10000
SELECT * FROM item WHERE id = 1 OR id = 2 ... id = 10000
This query took 0.1239 seconds
SELECT * FROM item WHERE id IN (1,2,3,...10000)
This query took 0.0433 seconds
IN is 3 times faster than OR
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Truncate (not round) decimal places in SQL Server
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select round(123.456, 2, 1)
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Get PostGIS version
...s like GEOS and proj4 you might want to get their versions too. Then use:
SELECT PostGIS_full_version();
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Data structure: insert, remove, contains, get random element, all at O(1)
...o other solutions).
The requirement that's tricky is the "random element" selection: in a hash table, you would need to scan or probe for such an element.
For closed hashing / open addressing, the chance of any given bucket being occupied is size() / capacity(), but crucially this is typically kep...