Module: Sequel::Plugins::FromCsv::ClassMethods

Defined in:
lib/sequel/plugins/from_csv.rb

Instance Method Summary collapse

Instance Method Details

#seed_from_csv(csv_path, delete_missing: false, reset_sequence: true) ⇒ Object

Synchronizes a table’s data with a CSV file



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# File 'lib/sequel/plugins/from_csv.rb', line 9

def seed_from_csv csv_path, delete_missing: false, reset_sequence: true

  # Read the source CSV file
  data = CSV.table csv_path

  # Ensure the ID column exists
  unless data.first[:id]
    raise "CSV file #{csv_path} must contain an id column"
  end

  self.db.transaction do

    # UPSERT
    data.each do |row|
      row = row.to_h # Convert CSV::Row to Hash
      self.dataset.insert_conflict(target: :id, update: row).insert row
    end

    # DELETE old rows
    if delete_missing
      self.exclude("id IN ?", data.map{|row| row[:id]}).delete
    end

    # Update the table's sequence
    if reset_sequence
      case self.db.database_type
      when :postgres
        self.db.run <<~SQL
          SELECT
            setval(pg_get_serial_sequence('#{self.simple_table}', 'id'), coalesce(max(id), 1), true)
          FROM
            #{self.simple_table}
        SQL
      end
    end

  end

end