Class: Rake::DataTask::Sqlite

Inherits:
Db
  • Object
show all
Includes:
NumericBooleans, StandardTransactions
Defined in:
lib/data_task/adapters/sqlite.rb

Constant Summary

Constants inherited from Db

Db::LOG, Db::TABLE_TRACKER_COLUMNS, Db::TABLE_TRACKER_NAME

Instance Method Summary collapse

Methods inherited from Db

#operation_values, #relation_type_values

Constructor Details

#initialize(options) ⇒ Sqlite

Connect to an Sqlite database.

Parameters:

  • options (Hash) —

    the connection parameters

Options Hash (options):

  • 'database' (String) —

    the database name



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# File 'lib/data_task/adapters/sqlite.rb', line 20

def initialize options
  @connection = SQLite3::Database.new(options['database'] || 'temp')

  # set up trackig if it isn't set up already
  set_up_tracking if !tracking_tables?
end

Instance Method Details

#[](name) ⇒ Object 



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# File 'lib/data_task/adapters/sqlite.rb', line 173

def [](name)
  Data.new(name, self)
end

#create_table(table_name, data_definition, column_definitions = nil, track_table = true) ⇒ Object Also known as: create_data 



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# File 'lib/data_task/adapters/sqlite.rb', line 80

def create_table table_name, data_definition, column_definitions=nil, track_table=true
  drop_table table_name
  execute <<-EOSQL
    create table #{table_name} #{column_definitions}
    #{ "as #{data_definition}" if !data_definition.nil? }
  EOSQL
  if track_table
    create_tracking_rules(table_name)
    track_creation table_name, 0
  end
end

#create_view(view_name, select_stmt) ⇒ Object 



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# File 'lib/data_task/adapters/sqlite.rb', line 117

def create_view view_name, select_stmt
  drop_view view_name
  execute "create view #{view_name} as #{select_stmt}"
end

#drop_table(table_name) ⇒ Object Also known as: drop_data 



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# File 'lib/data_task/adapters/sqlite.rb', line 94

def drop_table table_name
  execute "drop table if exists #{table_name}"

  # manually cascade the drop operation to views for this table
  views_for_dropped_table = execute <<-EOSQL
    select name from sqlite_master 
    where 
      type = 'view' and (
        -- add trailing space for views without where statements
        sql || ' ' like "% from #{table_name} %" or
        sql like "% join #{table_name} %"
      )
  EOSQL
  views_for_dropped_table.flatten.each do |view_name|
    drop_view view_name
  end

  return if table_name.casecmp(TABLE_TRACKER_NAME) == 0
  track_drop table_name
end

#drop_view(view_name) ⇒ Object 



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# File 'lib/data_task/adapters/sqlite.rb', line 122

def drop_view view_name
  execute "drop view if exists #{view_name}"
end

#execute(sql) ⇒ Object 



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# File 'lib/data_task/adapters/sqlite.rb', line 27

def execute sql
  connect if @connection.nil?
  begin
    @connection.execute sql
  rescue SQLite3::SQLException => e
    LOG.info e.message.chomp
    raise e
  end
end

#operations_supported ⇒ Object 



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# File 'lib/data_task/adapters/sqlite.rb', line 166

def operations_supported
  {
    :by_db => operations_supported_by_db,
    :by_app => [:truncate, :create]
  }
end

#reset_tracking(options = {}) ⇒ Object 



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# File 'lib/data_task/adapters/sqlite.rb', line 63

def reset_tracking options = {}
  truncate_table TABLE_TRACKER_NAME
end

#set_up_tracking(options = {}) ⇒ Object 



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# File 'lib/data_task/adapters/sqlite.rb', line 51

def set_up_tracking options = {}
  tear_down_tracking options
  column_definitions = table_tracker_columns.map do |col,col_defn|
    col.to_s + ' ' + col_defn[:data_type].to_s
  end.join(', ')
  create_table TABLE_TRACKER_NAME, nil, " (#{column_definitions})", false
end

#table_exists?(table_name, options = {}) ⇒ Boolean Also known as: data_exists?

Returns:

  • (Boolean) 


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# File 'lib/data_task/adapters/sqlite.rb', line 135

def table_exists? table_name, options = {}
  relation_exists?(table_name, 'table', options)
end

#table_mtime(table_name) ⇒ Object Also known as: data_mtime 



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# File 'lib/data_task/adapters/sqlite.rb', line 67

def table_mtime table_name
  Sql.get_single_time(
  execute <<-EOSQL
    -- assume time is UTC (Sqlite3 default) and add offset for Ruby's Time.parse 
    select datetime(max(time)) || ' -0000'
    from #{TABLE_TRACKER_NAME} 
    where relation_name = '#{table_name}'
  EOSQL
  )
end

#table_tracker_columns ⇒ Object 



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# File 'lib/data_task/adapters/sqlite.rb', line 44

def table_tracker_columns
  # replace the default datatype for time with SQLite's timestamp
  super.merge({
    :time => {:data_type => :timestamp}
  })
end

#tear_down_tracking(options = {}) ⇒ Object 



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# File 'lib/data_task/adapters/sqlite.rb', line 59

def tear_down_tracking options = {}
  drop_table TABLE_TRACKER_NAME
end

#track_drop(table_name) ⇒ Object 



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# File 'lib/data_task/adapters/sqlite.rb', line 126

def track_drop table_name
  execute <<-EOSQL
    delete from #{TABLE_TRACKER_NAME} 
    where 
      relation_name = '#{table_name}' and 
      relation_type = '#{relation_type_values[:table]}'
  EOSQL
end

#track_truncate(table_name) ⇒ Object 



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# File 'lib/data_task/adapters/sqlite.rb', line 153

def track_truncate table_name
  execute <<-EOSQL
    update #{TABLE_TRACKER_NAME}
    set 
      operation = '#{operation_values[:truncate]}',
      -- Sqlite generates times at UTC and stores them without zone information
      time = datetime('now')
    where
      relation_name = '#{table_name}' and
      relation_type = '#{relation_type_values[:table]}'
  EOSQL
end

#tracking_tables? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/data_task/adapters/sqlite.rb', line 40

def tracking_tables?
  table_exists?(TABLE_TRACKER_NAME)
end

#truncate_table(table_name) ⇒ Object Also known as: truncate_data 



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# File 'lib/data_task/adapters/sqlite.rb', line 145

def truncate_table table_name
  return if table_name.casecmp(TABLE_TRACKER_NAME) == 0
  execute "delete from #{table_name}"
  track_truncate table_name
end

#view_exists?(table_name, options = {}) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/data_task/adapters/sqlite.rb', line 141

def view_exists? table_name, options = {}
  relation_exists?(table_name, 'view', options)
end