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Checking if a variable is not nil and not zero in ruby
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You could do this:
if (!discount.nil? && !discount.zero?)
The order is important here, because if discount is nil, then it will not have a zero? method. Ruby's short-circuit evaluation should prevent it from trying to evaluate discount.zero?, however, if discount is nil.
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Entity Attribute Value Database vs. strict Relational Model Ecommerce
... information.
CREATE OR REPLACE VIEW sales_flat_addresses AS
SELECT sales_order_entity.parent_id AS order_id,
sales_order_entity.entity_id,
CONCAT(CONCAT(UCASE(MID(sales_order_entity_varchar.value,1,1)),MID(sales_order_entity_varchar.value,2)), "Address") as type,
GROUP_CONC...
Detect If Browser Tab Has Focus
... API without a prefix for a while now. I kept Microsoft specific prefix in order to stay compatible with IE10.
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How to append one file to another in Linux from the shell?
...w-zero-length file onto itself. This makes sense when you think about the order in which the operations could and should occur but is subtle enough that it catches many people by surprise. So if nothing else, eumiro and you have prompted a further improvement to the answer. Thanks for that!
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do { … } while (0) — what is it good for? [duplicate]
..., you don't get to choose how other people are going to use your macro. In order to avoid unexpected surprises inflicted upon your users, you have to use a technique like the above to make your macro behave as any other C statement would behave.
– Greg Hewgill
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How to order citations by appearance using BibTeX?
By default (using the plain style) BibTeX orders citations alphabetically.
12 Answers
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How to randomly select rows in SQL?
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SELECT TOP 5 Id, Name FROM customerNames
ORDER BY NEWID()
That said, everybody seems to come to this page for the more general answer to your question:
Selecting a random row in SQL
Select a random row with MySQL:
SELECT column FROM table
ORDER BY RAND()
LIMIT ...
Makefile, header dependencies
...n the object files, when it should obviously be on the sources and had the order of dependency wrong for the two targets, too. That's what I get for typing from memory. Try it now.
– dmckee --- ex-moderator kitten
Aug 23 '11 at 21:15
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How to find the php.ini file used by the command line?
...t my answer...in my case I type sudo find / -iname php.ini and it founds /etc/php/7.0/apache2/php.ini the right place of the right php.ini config file of my machine that it wasn't found by php --ini or php -i | grep php.ini (both found /etc/php/7.0/cli/php.ini)
– NineCattoRule...
Objective-C: Property / instance variable in category
...just an extension to it that avoids writing too much boilerplate code.
In order to avoid writing repeatedly getter and setter methods for category properties this answer introduces macros. Additionally these macros ease the use of primitive type properties such as int or BOOL.
Traditional approach...