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Rails: How can I set default values in ActiveRecord?
...st this case like so:
self.number ||= 0.0 if self.has_attribute? :number
and for a boolean column...
self.bool_field = true if (self.has_attribute? :bool_value) && self.bool_field.nil?
Also note that the syntax is different prior to Rails 3.2 (see Cliff Darling's comment below)
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Space between two rows in a table?
...class spaceUnder. This will make it possible to use nested tables. (Cell C and D in the example code.) I'm not too sure about browser support for the direct child selector (think IE 6), but it shouldn't break the code in any modern browsers.
/* Apply padding to td elements that are direct child...
Assign variable in if condition statement, good practice or not? [closed]
...ng whatever the value evaluates to be after the assignment. Is this understanding right?
– Michael Mao
Apr 5 '10 at 2:10
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What's the difference between session.Merge and session.SaveOrUpdate?
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if the object is versioned (by a <version> or <timestamp>), and the
version property value is the same value assigned to a newly
instantiated object, save() it
otherwise update() the object
and merge() is very different:
if there is a persistent instance with t...
Git 'fatal: Unable to write new index file'
I've seen many of the other threads about this and they don't help.
24 Answers
24
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Are non-synchronised static methods thread safe if they don't modify static class variables?
...lity, etc.
This method only operates on parameters, which reside on stack and references to immutable objects on heap. Stack is inherently local to the thread, so no sharing of data occurs, ever.
Immutable objects (String in this case) are also thread-safe because once created they can't be change...
Is std::vector copying the objects with a push_back?
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Yes, std::vector<T>::push_back() creates a copy of the argument and stores it in the vector. If you want to store pointers to objects in your vector, create a std::vector<whatever*> instead of std::vector<whatever>.
However, you need to make sure that the objects referenced...
Eclipse git checkout (aka, revert)
...Staging" view, right click the deleted file in the "Unstaged Changes" list and select "Replace with HEAD Revision"
– Vlasta Dolejs
Sep 5 '17 at 8:03
add a comment
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Openstreetmap: embedding map in webpage (like Google Maps)
...an example at http://wiki.openstreetmap.org/wiki/OpenLayers_Simple_Example and something more advanced at
http://wiki.openstreetmap.org/wiki/OpenLayers_Marker
and
http://wiki.openstreetmap.org/wiki/Openlayers_POI_layer_example
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Could not load file or assembly 'xxx' or one of its dependencies. An attempt was made to load a prog
...ecked out a revision from Subversion to a new folder. Opened the solution and I get this when run:
9 Answers
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