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Is there documentation for the Rails column types?
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Guidelines built from personal experience:
String:
Limited to 255 characters (depending on DBMS)
Use for short text fields (names, emails, etc)
Text:
Unlimited length (depending on DBMS)
Use for comments, blog posts, etc. General rule ...
Finding out whether a string is numeric or not
... check if a string is made up of numbers only. I am taking out a substring from a string and want to check if it is a numeric substring or not.
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Difference between declaring variables before or in loop?
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Which is better, a or b?
From a performance perspective, you'd have to measure it. (And in my opinion, if you can measure a difference, the compiler isn't very good).
From a maintenance perspective, b is better. Declare and initialize variables in t...
Android Paint: .measureText() vs .getTextBounds()
...result of measureText.
It's seen that bounds left part starts some pixels from left, and value of measureText is incremented by this value on both left and right. This is something called Glyph's AdvanceX value. (I've discovered this in Skia sources in SkPaint.cpp)
So the outcome of the test is th...
How do I check whether a jQuery element is in the DOM?
...s I was typing my question: Call
$foo.parent()
If $f00 has been removed from the DOM, then $foo.parent().length === 0. Otherwise, its length will be at least 1.
[Edit: This is not entirely correct, because a removed element can still have a parent; for instance, if you remove a <ul>, each...
How to remove all .svn directories from my application directories
...n export tool I have in my application, is to clean all .svn directories from my application directory tree. I am looking for a recursive command in the Linux shell that will traverse the entire tree and delete the .svn files.
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Correct way to populate an Array with a Range in Ruby
.... But this creates another array inside the array, I simply want the range from 2 to 25. Yet if I try order << (2.25) I get the error can't convert Range into Integer.
– kakubei
Nov 10 '11 at 14:29
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What are the differences between virtual memory and physical memory?
...ocesses to have their own address spaces. This protects one process's data from being written over by another process. It also lets you give different permissions to different address spaces, so some users of the system can have higher read/write privileges than others. Having the same amount of vir...
Automatic prune with Git fetch or pull
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To accommodate users who want to either prune always or when fetching from a particular remote, add two new configuration variables "fetch.prune" and "remote.<name>.prune":
"fetch.prune" allows to enable prune for all fetch operations.
"remote.<name>.prune" allows to chang...
What is the meaning of the CascadeType.ALL for a @ManyToOne JPA association
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See here for an example from the OpenJPA docs. CascadeType.ALL means it will do all actions.
Quote:
CascadeType.PERSIST: When persisting an entity, also persist the entities held in its fields. We suggest a liberal application of this cascade rule,...