Class: SQLite3::Database::FunctionProxy

Inherits:
Object
  • Object
show all
Defined in:
lib/sqlite3/database.rb

Overview

A helper class for dealing with custom functions (see #create_function, #create_aggregate, and #create_aggregate_handler). It encapsulates the opaque function object that represents the current invocation. It also provides more convenient access to the API functions that operate on the function object.

This class will almost always be instantiated indirectly, by working with the create methods mentioned above.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ FunctionProxy

Create a new FunctionProxy that encapsulates the given func object. If context is non-nil, the functions context will be set to that. If it is non-nil, it must quack like a Hash. If it is nil, then none of the context functions will be available.



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# File 'lib/sqlite3/database.rb', line 537

def initialize
  @result   = nil
  @context  = {}
end

Instance Attribute Details

#result ⇒ Object

Returns the value of attribute result.



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# File 'lib/sqlite3/database.rb', line 531

def result
  @result
end

Instance Method Details

#[](key) ⇒ Object

Returns the value with the given key from the context. This is only available to aggregate functions.



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# File 'lib/sqlite3/database.rb', line 557

def []( key )
  @context[ key ]
end

#[]=(key, value) ⇒ Object

Sets the value with the given key in the context. This is only available to aggregate functions.



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# File 'lib/sqlite3/database.rb', line 563

def []=( key, value )
  @context[ key ] = value
end

#count ⇒ Object

(Only available to aggregate functions.) Returns the number of rows that the aggregate has processed so far. This will include the current row, and so will always return at least 1.



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# File 'lib/sqlite3/database.rb', line 551

def count
  @driver.aggregate_count( @func )
end

#set_error(error) ⇒ Object

Set the result of the function to the given error message. The function will then return that error.



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# File 'lib/sqlite3/database.rb', line 544

def set_error( error )
  @driver.result_error( @func, error.to_s, -1 )
end