Class: Amalgalite::TypeMaps::DefaultMap

Inherits:
Object
  • Object
show all
Defined in:
lib/amalgalite/type_maps/default_map.rb

Overview

An Amalgalite::TypeMap that does its best to convert between Ruby classes and known SQL data types.

Upon instantiation, DefaultMap generates a conversion map to try to figure out the best way to convert between populate SQL ‘types’ and ruby classes

Constant Summary collapse

SQL_TO_METHOD = 
{
  'date'      => 'date',
  'datetime'  => 'datetime',
  'timestamp' => 'time',
  'time'      => 'time',

  'double'    => 'float',
  'float'     => 'float',
  'real'      => 'float',
  'numeric'   => 'float',
  'decimal'   => 'float',

  'integer'   => 'integer',
  'tinyint'   => 'integer',
  'smallint'  => 'integer',
  'int'       => 'integer',
  'int2'      => 'integer',
  'int4'      => 'integer',
  'int8'      => 'integer',
  'bigint'    => 'integer',
  'serial'    => 'integer',
  'bigserial' => 'integer',

  'text'      => 'string',
  'char'      => 'string',
  'string'    => 'string',
  'varchar'   => 'string',
  'character' => 'string',
  'json'      => 'string',

  'bool'      => 'boolean',
  'boolean'   => 'boolean',

  'blob'      => 'blob',
  'binary'    => 'blob',
}.freeze

Instance Method Summary collapse

Instance Method Details

#bind_type_of(obj) ⇒ Object

A straight logical mapping (for me at least) of basic Ruby classes to SQLite types, if nothing can be found then default to TEXT.



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# File 'lib/amalgalite/type_maps/default_map.rb', line 59

def bind_type_of( obj )
  case obj
  when Float
    ::Amalgalite::SQLite3::Constants::DataType::FLOAT
  when Integer
    ::Amalgalite::SQLite3::Constants::DataType::INTEGER
  when NilClass
    ::Amalgalite::SQLite3::Constants::DataType::NULL
  when ::Amalgalite::Blob
    ::Amalgalite::SQLite3::Constants::DataType::BLOB
  else
    ::Amalgalite::SQLite3::Constants::DataType::TEXT
  end
end

#blob(str) ⇒ Object

convert a string to a blob



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# File 'lib/amalgalite/type_maps/default_map.rb', line 154

def blob( str )
  ::Amalgalite::Blob.new( :string => str )
end

#boolean(str) ⇒ Object

convert a string to true of false



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# File 'lib/amalgalite/type_maps/default_map.rb', line 147

def boolean( str )
  ::Amalgalite::Boolean.to_bool( str )
end

#date(str) ⇒ Object

convert a string to a date



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# File 'lib/amalgalite/type_maps/default_map.rb', line 104

def date( str )
  Date.parse( str )
end

#datetime(str) ⇒ Object

convert a string to a datetime, if no timzone is found in the parsed string, set it to the local offset.



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# File 'lib/amalgalite/type_maps/default_map.rb', line 112

def datetime( str )
  DateTime.parse( str )
end

#float(str) ⇒ Object

convert a string to a Float



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# File 'lib/amalgalite/type_maps/default_map.rb', line 126

def float( str )
  Float( str )
end

#integer(str) ⇒ Object

convert an string to an Integer



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# File 'lib/amalgalite/type_maps/default_map.rb', line 133

def integer( str )
  Float( str ).to_i
end

#result_value_of(normalized_declared_type, value) ⇒ Object

Map the incoming value to an outgoing value. For some incoming values, there will be no change, but for some (i.e. Dates and Times) there is some conversion.

It is assumed that ‘normalized_declared_type` is a downcased string. This assumption is made for performance reasons as this method is called many times during the returning of data from a query.



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# File 'lib/amalgalite/type_maps/default_map.rb', line 83

def result_value_of( normalized_declared_type, value )
  case value
  when Numeric, NilClass, Amalgalite::Blob
    return value
  when String
    return value unless normalized_declared_type

    conversion_method = DefaultMap::SQL_TO_METHOD[normalized_declared_type]
    if conversion_method then
      return send(conversion_method, value)
    else
      raise ::Amalgalite::Error, "Unable to convert SQL type of #{normalized_declared_type} to a Ruby class"
    end
  else
    raise ::Amalgalite::Error, "Unable to convert a class #{value.class.name} with value #{value.inspect}"
  end
end

#string(str) ⇒ Object

convert a string to a String, yes redundant I know.



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# File 'lib/amalgalite/type_maps/default_map.rb', line 140

def string( str )
  str
end

#time(str) ⇒ Object

convert a string to a Time



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# File 'lib/amalgalite/type_maps/default_map.rb', line 119

def time( str )
  Time.parse( str )
end