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“INSERT IGNORE” vs “INSERT … ON DUPLICATE KEY UPDATE”
...ON DUPLICATE KEY UPDATE.
If you use INSERT IGNORE, then the row won't actually be inserted if it results in a duplicate key. But the statement won't generate an error. It generates a warning instead. These cases include:
Inserting a duplicate key in columns with PRIMARY KEY or UNIQUE constrain...
How to reverse a 'rails generate'
I want to delete all the files it created and roll back any changes made, but not necessarily to the database, but more to the config files.
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Uniq by object attribute in Ruby
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Do it on the database level:
YourModel.find(:all, :group => "status")
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How to delete an item in a list if it exists?
...emethod will remove only the first occurrence of thing, in order to remove all occurrences you can use while instead of if.
while thing in some_list: some_list.remove(thing)
Simple enough, probably my choice.for small lists (can't resist one-liners)
2) Duck-typed, EAFP style:
This shoot-f...
How to move columns in a MySQL table?
...erform on a large table? Is it just changing some metadata, or does it actually have to reorganize data on the disk?
– Kip
Nov 12 '15 at 16:01
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Show loading image while $.ajax is performed
...te: function(){
$('#loading-image').hide();
}
});
I usually prefer the more general solution of binding it to the global ajaxStart and ajaxStop events, that way it shows up for all ajax events:
$('#loading-image').bind('ajaxStart', function(){
$(this).show();
}).bind('ajaxSt...
What is a StackOverflowError?
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Parameters and local variables are allocated on the stack (with reference types, the object lives on the heap and a variable in the stack references that object on the heap). The stack typically lives at the upper end of your address space and as it is used up...
Put buttons at bottom of screen with LinearLayout?
...d:gravity="center|bottom"
Notice that fill_parent does not mean "take up all available space". However, if you use layout_height="0dp" with layout_weight="1", then a view will take up all available space (Can't get proper layout with "fill_parent").
Here is some code I quickly wrote up that uses ...
Is it possible to get element from HashMap by its position?
How to retrieve an element from HashMap by its position, is it possible at all?
14 Answers
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How do you design object oriented projects? [closed]
.... If you're a Java developer, NetBeans 6.7 from Sun has a UML module that allows for diagramming as well as round-trip engineering and it's FREE. Eclipse (an open source Java IDE), also has a modeling framework, but I have no experience with it. You may also want to try out ArgoUML, an open sour...