Class: MotionRecord::ConnectionAdapters::SQLiteAdapter

Inherits:
Object
  • Object
show all
Defined in:
lib/motion_record/connection_adapters/sqlite_adapter.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(file, debug = true) ⇒ SQLiteAdapter

Returns a new instance of SQLiteAdapter.



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# File 'lib/motion_record/connection_adapters/sqlite_adapter.rb', line 62

def initialize(file, debug=true)
  @db = SQLite3::Database.new(file)
  @db.logging = debug
end

Class Method Details

.configure(options = {}) ⇒ Object

Configure the SQLite connection

options - Hash of configuration options for the SQLite connection

:file - full name of the database file, or :memory for
        in-memory database files (default is "app.sqlite3"
        in the app's `/Library/Application Support` folder)
:debug - set to false to turn off SQL debug logging



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# File 'lib/motion_record/connection_adapters/sqlite_adapter.rb', line 12

def configure(options={})
  @configuration_options = options
end

.debug? ⇒ Boolean

Returns true if debug logging is enabled for the database

Returns:

  • (Boolean) 


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# File 'lib/motion_record/connection_adapters/sqlite_adapter.rb', line 34

def debug?
  if @configuration_options.has_key?(:debug)
    !!@configuration_options[:debug]
  else
    true
  end
end

.filename ⇒ Object

Full filename of the database file



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# File 'lib/motion_record/connection_adapters/sqlite_adapter.rb', line 21

def filename
  if (file = @configuration_options[:file])
    if file == :memory
      ":memory:"
    else
      file
    end
  else
    create_default_database_file
  end
end

.instance ⇒ Object 



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# File 'lib/motion_record/connection_adapters/sqlite_adapter.rb', line 16

def instance
  @instance ||= ConnectionAdapters::SQLiteAdapter.new(filename, debug?)
end

Instance Method Details

#calculate(scope, method, column) ⇒ Object

Run a calculation on a set of rows

scope - MotionRecord::Scope which defines the set of rows method - one of :count, :maximum, :minimum, :sum, :average column - name of the column to run the calculation on

Returns the numerical value of calculation or nil if there were no rows in the scope



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# File 'lib/motion_record/connection_adapters/sqlite_adapter.rb', line 133

def calculate(scope, method, column)
  case method
  when :count
    calculation = "COUNT(#{column || "*"})"
  when :maximum
    calculation = "MAX(#{column})"
  when :minimum
    calculation = "MIN(#{column})"
  when :sum
    calculation = "SUM(#{column})"
  when :average
    calculation = "AVG(#{column})"
  else
    raise "Unrecognized calculation: #{method.inspect}"
  end

  calculate_statement = "SELECT #{calculation} AS #{method} FROM #{scope.klass.table_name} #{scope.predicate}"

  if (row = @db.execute(calculate_statement, scope.predicate_values).first)
    row[method]
  else
    nil
  end
end

#delete(scope) ⇒ Object

Delete rows from a table

scope - MotionRecord::Scope defining the set of rows to delete



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# File 'lib/motion_record/connection_adapters/sqlite_adapter.rb', line 119

def delete(scope)
  delete_statement = "DELETE FROM #{scope.klass.table_name} #{scope.predicate}"

  @db.execute delete_statement, scope.predicate_values
end

#execute(command) ⇒ Object 



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# File 'lib/motion_record/connection_adapters/sqlite_adapter.rb', line 67

def execute(command)
  @db.execute(command)
end

#insert(table_name, params) ⇒ Object

Add a row to a table

table_name - name of the table params - Hash of column names to values to insert



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# File 'lib/motion_record/connection_adapters/sqlite_adapter.rb', line 90

def insert(table_name, params)
  pairs = params.to_a
  param_names  = pairs.map(&:first)
  param_values = pairs.map(&:last)
  param_marks = Array.new(param_names.size, "?").join(", ")

  insert_statement = "INSERT INTO #{table_name} (#{param_names.join(", ")}) VALUES (#{param_marks})"

  @db.execute insert_statement, param_values
end

#select(scope) ⇒ Object

Load all records for a scope

scope - A MotionRecord::Scope

Returns an Array of row Hashes



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# File 'lib/motion_record/connection_adapters/sqlite_adapter.rb', line 81

def select(scope)
  select_statement = "SELECT * FROM #{scope.klass.table_name} #{scope.predicate}"
  @db.execute(select_statement, scope.predicate_values)
end

#table_exists?(table_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/motion_record/connection_adapters/sqlite_adapter.rb', line 71

def table_exists?(table_name)
  # FIXME: This statement is totally vulnerable to SQL injection
  @db.execute("SELECT name FROM sqlite_master WHERE type='table' AND name='#{table_name}'").any?
end

#update(scope, params) ⇒ Object

Add a row to a table

scope - A MotionRecord::Scope params - Hash of column names to values to update



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# File 'lib/motion_record/connection_adapters/sqlite_adapter.rb', line 105

def update(scope, params)
  pairs = params.to_a
  param_names  = pairs.map(&:first)
  param_values = pairs.map(&:last)
  param_marks  = param_names.map { |param| "#{param} = ?" }.join(", ")

  update_statement = "UPDATE #{scope.klass.table_name} SET #{param_marks} #{scope.predicate}"

  @db.execute update_statement, param_values + scope.predicate_values
end