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Map and Reduce in .NET
...ons. C# 3.5 and Linq already has it albeit under different names.
Map is Select:
Enumerable.Range(1, 10).Select(x => x + 2);
Reduce is Aggregate:
Enumerable.Range(1, 10).Aggregate(0, (acc, x) => acc + x);
Filter is Where:
Enumerable.Range(1, 10).Where(x => x % 2 == 0);
https://www...
How can I check if a View exists in a Database?
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FOR SQL SERVER
IF EXISTS(select * FROM sys.views where name = '')
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T-SQL datetime rounded to nearest minute and nearest hours with using functions
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declare @dt datetime
set @dt = '09-22-2007 15:07:38.850'
select dateadd(mi, datediff(mi, 0, @dt), 0)
select dateadd(hour, datediff(hour, 0, @dt), 0)
will return
2007-09-22 15:07:00.000
2007-09-22 15:00:00.000
The above just truncates the seconds and minutes, producing the resu...
How do I select the parent form based on which submit button is clicked?
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You can select the form like this:
$("#submit").click(function(){
var form = $(this).parents('form:first');
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});
However, it is generally better to attach the event to the submit event of the form itself, as it will tri...
Why use the INCLUDE clause when creating an index?
...ot in the WHERE/JOIN/GROUP BY/ORDER BY, but only in the column list in the SELECT clause.
The INCLUDE clause adds the data at the lowest/leaf level, rather than in the index tree.
This makes the index smaller because it's not part of the tree
INCLUDE columns are not key columns in the index, so th...
Getting attribute using XPath
...e), for
the first element?
Use:
/*/book[1]/title/@lang
This means:
Select the lang attribute of the title element that is a child of the first book child of the top element of the XML document.
To get just the string value of this attribute use the standard XPath function string():
string(...
How to change Xcode Project name
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For Xcode 4 or later:
Open a project
Select Project Navigator
Highlight project name
Single click on project name
For Xcode 3:
Open a project > Menu > Project > Rename ...
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SQL - Rounding off to 2 decimal places
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Could you not cast your result as numeric(x,2)? Where x <= 38
select
round(630/60.0,2),
cast(round(630/60.0,2) as numeric(36,2))
Returns
10.500000 10.50
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Psql list all tables
...This is where the INFORMATION_SCHEMA comes to the rescue. To list tables:
SELECT table_name FROM information_schema.tables WHERE table_schema = 'public';
BTW, if you ever want to see what psql is doing in response to a backslash command, run psql with the -E flag. eg:
$ psql -E regress
regre...
Postgres: Distinct but only for one column
...h names (having more than 1 mio. rows), but I have also many duplicates. I select 3 fields: id , name , metadata .
3 Ans...