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Can someone explain collection_select to me in clear, simple terms?
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This is easily, one of the best explanations of a complex Rails structure I have seen. You used clear language, along with basic Rails constructs to solidify it. Thanks much!!
– marcamillion
Jan 19 '12 ...
Renaming table in rails
...o change the name of the model or want to retain the model name as the old one? If so you may want to specify the table name in the ActiveRecord model using "set_table_name :bar".
– Aditya Sanghi
Jan 8 '11 at 10:27
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What exactly does big Ө notation represent?
... related to the best, worst and average cases analysis of algorithms. Each one of these can be applied to each analysis.
We usually use it to analyze complexity of algorithms (like the merge sort example above). When we say "Algorithm A is O(f(n))", what we really mean is "The algorithms complexity ...
WPF Data Binding and Validation Rules Best Practices
...cting an incoming bad
value and throwing an exception. If
the ValidatesOnExceptions property on
the data binding is true, the data
binding engine in WPF and Silverlight
will handle the exception and display
a visual cue to the user that there is
a data validation error.
However, t...
What are Runtime.getRuntime().totalMemory() and freeMemory()?
...Xmx - size of a single survivor space. Why? Because at the same time, only one survivor space can be used.
– G. Demecki
Mar 17 '17 at 11:13
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What is q=0.5 in Accept* HTTP headers?
...ality factor in the specification:
Each media-range MAY be followed by one or more accept-params,
beginning with the "q" parameter for indicating a relative quality
factor. The first "q" parameter (if any) separates the media-range
parameter(s) from the accept-params. Quality factors allow...
What is a callback URL in relation to an API?
...my case I have a few callback URLs that I have to define myself. A popular one is a "default callback URL". What is this exactly? Can you give an example in plain english?
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Determine the type of an object?
...s well, which has the great advantage that you can capture subclasses. someone using OrderedDict would hate your code to fail because it just accepts pure dicts.
– flying sheep
Oct 27 '12 at 11:12
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PHP foreach change original array values
... provided any explanation why this solution would be better than the other ones, or how it works at all..
– Dharman
Nov 15 '18 at 13:29
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How to perform OR condition in django queryset?
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Both options are already mentioned in the existing answers:
from django.db.models import Q
q1 = User.objects.filter(Q(income__gte=5000) | Q(income__isnull=True))
and
q2 = User.objects.filter(income__gte=5000) | User.objects.filter(income__isnull=True)...