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WITH CHECK ADD CONSTRAINT followed by CHECK CONSTRAINT vs. ADD CONSTRAINT
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It doesn't look like WITH CHECK is actually the default, it's only the default for new data. From msdn.microsoft.com/en-us/library/ms190273.aspx: "If not specified, WITH CHECK is assumed for new constraints, and WITH NOCHECK is assumed for re-enabled constraints."...
How do you convert a DataTable into a generic list?
...e DataTableExtensions.AsEnumerable (an extension method) and then if you really need a List<DataRow> instead of just IEnumerable<DataRow> you can call Enumerable.ToList:
IEnumerable<DataRow> sequence = dt.AsEnumerable();
or
using System.Linq;
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List<DataRow> list = dt.A...
How to convert nanoseconds to seconds using the TimeUnit enum?
... This answer is now wrong - convert() and the toFoo() methods all return longs now docs.oracle.com/javase/6/docs/api/java/util/concurrent/…
– Riking
Jul 30 '13 at 1:58
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How can i tell if an object has a key value observer attached
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Put a try catch around your removeObserver call
@try{
[someObject removeObserver:someObserver forKeyPath:somePath];
}@catch(id anException){
//do nothing, obviously it wasn't attached because an exception was thrown
}
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Best way to select random rows PostgreSQL
...lass WHERE oid = 'schema_name.big'::regclass;
As long as ct isn't much smaller than id_span, the query will outperform other approaches.
WITH params AS (
SELECT 1 AS min_id -- minimum id <= current min id
, 5100000 AS id_span -- rounded up. (max_id - m...
Converting strings to floats in a DataFrame
...newer version of pandas (0.17 and up), you can use to_numeric function. It allows you to convert the whole dataframe or just individual columns. It also gives you an ability to select how to treat stuff that can't be converted to numeric values:
import pandas as pd
s = pd.Series(['1.0', '2', -3])
p...
Do sealed classes really offer performance Benefits?
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The JITter will sometimes use non-virtual calls to methods in sealed classes since there is no way they can be extended further.
There are complex rules regarding calling type, virtual/nonvirtual, and I don't know them all so I can't really outline them for you, but ...
How do I recursively delete a directory and its entire contents (files + sub dirs) in PHP?
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This calls is_dir twice for each recursed directory. If the argument is a symlink, it also follows it instead of deleting the symlink, which might or might not be what you want. In any case, it's not what rm -rf does.
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Move capture in lambda
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Generalized lambda capture in C++14
In C++14 we will have the so called generalized lambda capture. This enables move capture. The following will be legal code in C++14:
using namespace std;
// a unique_ptr is move-only
auto u = make_unique<some_type>( some, parameters );
// move...
Add Variables to Tuple
... I think its important to note that tuples are immutable - they cannot actually be modified. What this solution does is create a new tuple based on two existing tuples.
– That1Guy
Jan 16 '19 at 20:58
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