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How do you run a SQL Server query from PowerShell?
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For others who need to do this with just stock .NET and PowerShell (no additional SQL tools installed) here is the function that I use:
function Invoke-SQL {
param(
[string] $dataSource = ".\SQLEXPRESS",
[...
Check if object is file-like in Python
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AttributeError can be raised for all sorts of reasons that have nothing to do with whether the object supports the interface you need. hasattr is needed for filelikes that don't derive from IOBase
– Erik Aronesty
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Postgresql SELECT if string contains
...LSE. The statement is not dynamic, only values are concatenated, no chance for SQL injection.
– Erwin Brandstetter
Apr 27 '14 at 10:48
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*.h or *.hpp for your class definitions
I've always used a *.h file for my class definitions, but after reading some boost library code, I realised they all use *.hpp . I've always had an aversion to that file extension, I think mainly because I'm not used to it.
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Convert tuple to list and back
I'm currently working on a map editor for a game in pygame, using tile maps.
The level is built up out of blocks in the following structure (though much larger):
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How can I alter a primary key constraint using SQL syntax?
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For those of you, not knowing the constraint name: ALTER TABLE db.table DROP PRIMARY KEY, ADD PRIMARY KEY (id1, id2);
– karsten314159
Dec 13 '18 at 12:24
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Deleting rows with MySQL LEFT JOIN
I have two tables, one for job deadlines, one for describe a job. Each job can take a status and some statuses means the jobs' deadlines must be deleted from the other table.
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Do I have to guard against SQL injection if I used a dropdown?
I understand that you should NEVER trust user input from a form, mainly due to the chance of SQL injection.
11 Answers
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How to get one value at a time from a generator function in Python?
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In Python <= 2.5, use gen.next(). This will work for all Python 2.x versions, but not Python 3.x
In Python >= 2.6, use next(gen). This is a built in function, and is clearer. It will also work in Python 3.
Both of these end up calling a specially named function, next()...
pandas GroupBy columns with NaN (missing) values
...in GroupBy are automatically excluded. This behavior is consistent with R, for example.
One workaround is to use a placeholder before doing the groupby (e.g. -1):
In [11]: df.fillna(-1)
Out[11]:
a b
0 1 4
1 2 -1
2 3 6
In [12]: df.fillna(-1).groupby('b').sum()
Out[12]:
a
b
-1...