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Rails: how do I validate that something is a boolean?
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245
Since Rails 3, you can do:
validates :field, inclusion: { in: [ true, false ] }
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#1071 - Specified key was too long; max key length is 1000 bytes
... left substring of the data. Most of your data will be a lot shorter than 255 characters anyway.
You can declare a prefix length per column as you define the index. For example:
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KEY `index` (`parent_menu_id`,`menu_link`(50),`plugin`(50),`alias`(50))
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But what's the best prefix length fo...
How exactly does the callstack work?
...to make room for local variables.
Then cin is moved into the EDI register2 and get is called; The return value is in EAX.
So far so good. Now the interesting thing happens:
The low-order byte of EAX, designated by the 8-bit register AL, is taken and stored in the byte right after the base pointe...
RabbitMQ message size and types
...ant to read up on their performance measures:
http://www.rabbitmq.com/blog/2012/04/17/rabbitmq-performance-measurements-part-1/
http://www.rabbitmq.com/blog/2012/04/25/rabbitmq-performance-measurements-part-2/
Queues are pretty light weight, you will most likely be limited by the number of connectio...
convert ArrayList to JSONArray
...:
http://developer.android.com/reference/org/json/JSONArray.html#JSONArray%28java.util.Collection%29
collection:
http://developer.android.com/reference/java/util/Collection.html
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Select by partial string from a pandas DataFrame
I have a DataFrame with 4 columns of which 2 contain string values. I was wondering if there was a way to select rows based on a partial string match against a particular column?
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How do you clear a slice in Go?
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123
It all depends on what is your definition of 'clear'. One of the valid ones certainly is:
slic...
Gson - convert from Json to a typed ArrayList
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529
You may use TypeToken to load the json string into a custom object.
logs = gson.fromJson(br, n...
Direct casting vs 'as' operator?
... Otherwise, assigns o to s, even if o is null.
string s = o as string; // 2
Assigns null to s if o is not a string or if o is null. For this reason, you cannot use it with value types (the operator could never return null in that case). Otherwise, assigns o to s.
string s = o.ToString(); // 3
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Invalid argument supplied for foreach()
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edited Oct 27 '15 at 20:57
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