Class: ActiveRecord::Tasks::DuckdbDatabaseTasks

Inherits:
Object
  • Object
show all
Defined in:
lib/active_record/tasks/duckdb_database_tasks.rb

Overview

Database tasks implementation for DuckDB adapter

Constant Summary collapse

MEMORY_MODE_KEYS =

Keys that indicate in-memory database mode

[:memory, 'memory', ':memory:', ':memory'].freeze
TRUE_VALUES = 
[true, 'true', 'TRUE', 1, '1'].freeze

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(db_config, root_path = ActiveRecord::Tasks::DatabaseTasks.root) ⇒ DuckdbDatabaseTasks

Initializes a new DuckDB database tasks instance

Parameters:

  • db_config (ActiveRecord::DatabaseConfigurations::DatabaseConfig) —

    Database configuration

  • root_path (String) (defaults to: ActiveRecord::Tasks::DatabaseTasks.root) —

    Root path for the Rails application



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# File 'lib/active_record/tasks/duckdb_database_tasks.rb', line 23

def initialize(db_config, root_path = ActiveRecord::Tasks::DatabaseTasks.root)
  @db_config = db_config
  @configuration_hash = db_config.configuration_hash
  @root_path = root_path
end

Class Method Details

.using_database_configurations? ⇒ Boolean

Indicates whether this adapter uses database configurations

Returns:

  • (Boolean) —

    always returns true



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# File 'lib/active_record/tasks/duckdb_database_tasks.rb', line 16

def self.using_database_configurations?
  true
end

Instance Method Details

#charset ⇒ String

Returns the character set used by DuckDB

Returns:

  • (String) —

    always returns ‘UTF-8’



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# File 'lib/active_record/tasks/duckdb_database_tasks.rb', line 72

def charset
  'UTF-8'
end

#collation ⇒ nil

Returns the collation used by DuckDB

Returns:

  • (nil) —

    always returns nil as DuckDB doesn’t use explicit collations



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# File 'lib/active_record/tasks/duckdb_database_tasks.rb', line 78

def collation
  nil
end

#create ⇒ void

This method returns an undefined value.

Creates a new DuckDB database file or skips if in-memory mode

Raises:

  • (StandardError) —

    if database creation fails



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# File 'lib/active_record/tasks/duckdb_database_tasks.rb', line 32

def create
  # For DuckDB, creating a database means creating the file (if not in-memory)
  database_path = @configuration_hash[:database]
  return if MEMORY_MODE_KEYS.include?(database_path)

  # Ensure the directory exists
  FileUtils.mkdir_p(File.dirname(database_path)) if database_path.include?('/')

  # Create the database file by opening a connection
  DuckDB::Database.open(database_path).connect.close
rescue StandardError => e
  warn "Couldn't create '#{database_path}' database. Please check your configuration."
  warn "Error: #{e.message}"
  raise
end

#drop ⇒ void

This method returns an undefined value.

Drops the DuckDB database by removing the database file

Raises:

  • (StandardError) —

    if database drop fails



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# File 'lib/active_record/tasks/duckdb_database_tasks.rb', line 51

def drop
  db_path = @configuration_hash[:database]
  return if MEMORY_MODE_KEYS.include?(db_path)

  db_file_path = File.absolute_path?(db_path) ? db_path : File.join(root_path, db_path)
  FileUtils.rm_f(db_file_path)
rescue StandardError => e
  warn "Couldn't drop database '#{db_path}'"
  warn "Error: #{e.message}"
  raise
end

#purge ⇒ void

This method returns an undefined value.

Purges the database by dropping and recreating it



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# File 'lib/active_record/tasks/duckdb_database_tasks.rb', line 65

def purge
  drop
  create
end

#structure_dump(filename, extra_flags = nil) ⇒ void

This method returns an undefined value.

Dumps the database structure to a SQL file

Parameters:

  • filename (String) —

    The filename to write the structure dump to

  • extra_flags (String, nil) (defaults to: nil) —

    Additional flags for the dump (unused)



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# File 'lib/active_record/tasks/duckdb_database_tasks.rb', line 86

def structure_dump(filename, extra_flags = nil)
  # Export the database schema
  establish_connection

  File.open(filename, 'w') do |file|
    # Get all tables using DuckDB's information schema
    tables_sql = "SELECT table_name FROM information_schema.tables WHERE table_schema = 'main' AND table_type = 'BASE TABLE'"
    tables = connection.query(tables_sql)

    tables.each do |table_row|
      table_name = table_row[0]
      next if %w[ar_internal_metadata schema_migrations].include?(table_name)

      # Get table schema using PRAGMA (DuckDB supports SQLite-compatible PRAGMA)
      table_info = connection.query("PRAGMA table_info('#{table_name}')")

      # Build CREATE TABLE statement
      # [[0, "id", "BIGINT", true, nil, true], [1, "name", "VARCHAR", false, 'default_value', false], [2, "email", "VARCHAR", false, nil, false], [3, "created_at", "TIMESTAMP", true, nil, false], [4, "updated_at", "TIMESTAMP", true, nil, false]]
      columns = table_info.map do |col|
        col_def = "#{col[1]} #{col[2]}"
        col_def += ' NOT NULL' if TRUE_VALUES.include?(col[3])
        col_def += " DEFAULT #{col[4]}" if col[4]
        col_def += ' PRIMARY KEY' if TRUE_VALUES.include?(col[5])
        col_def
      end

      file.puts "CREATE TABLE #{table_name} ("
      file.puts "  #{columns.join(",\n  ")}"
      file.puts ');'
      file.puts
    end

    # Get list of sequences used for the table
    sequences = connection.query('SELECT sequencename, start_value, min_value, max_value, increment_by, cycle FROM pg_catalog.pg_sequences').to_a

    # Build CREATE SEQUENCE statements
    sequences.each do |seq|
      seq_def = "CREATE SEQUENCE #{seq[0]}"
      seq_def += " START WITH #{seq[1]}" if seq[1] && seq[1] != 1
      seq_def += " INCREMENT BY #{seq[4]}" if seq[4] && seq[4] != 1
      seq_def += " MINVALUE #{seq[2]}" if seq[2] != -9_223_372_036_854_775_808
      seq_def += " MAXVALUE #{seq[3]}" if seq[3] != 9_223_372_036_854_775_807
      seq_def += ' CYCLE' if seq[5]
      seq_def += ';'
      file.puts seq_def
    end
  end
end

#structure_load(filename, extra_flags = nil) ⇒ void

This method returns an undefined value.

Loads database structure from a SQL file

Parameters:

  • filename (String) —

    The filename to load the structure from

  • extra_flags (String, nil) (defaults to: nil) —

    Additional flags for the load (unused)

Raises:

  • (LoadError) —

    if the schema file does not exist



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# File 'lib/active_record/tasks/duckdb_database_tasks.rb', line 140

def structure_load(filename, extra_flags = nil)
  establish_connection
  raise(LoadError, 'Database scheme file does not exist') unless File.exist?(filename)

  sql = File.read(filename)
  connection.query(sql)
end