module SQLite3::Pragmas - sqlite3-1.3.13 Documentation

# module SQLite3::Pragmas

This module is intended for inclusion solely by the Database class. It defines convenience methods for the various pragmas supported by SQLite3.

For a detailed description of these pragmas, see the SQLite3 documentation at sqlite.org/pragma.html.

### Constants

AUTO_VACUUM_MODES

  The enumeration of valid auto vacuum modes.

ENCODINGS

  The list of valid encodings.

JOURNAL_MODES

  The list of valid journaling modes.

LOCKING_MODES

  The list of valid locking modes.

SYNCHRONOUS_MODES

  The enumeration of valid synchronous modes.

TEMP_STORE_MODES

  The enumeration of valid temp store modes.

WAL_CHECKPOINTS

  The list of valid WAL checkpoints.

### Public Instance Methods

application_id() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 104
    def application_id
      get_int_pragma "application_id"
    end

application_id=( integer ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 108
    def application_id=( integer )
      set_int_pragma "application_id", integer
    end

auto_vacuum() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 112
    def auto_vacuum
      get_enum_pragma "auto_vacuum"
    end

auto_vacuum=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 116
    def auto_vacuum=( mode )
      set_enum_pragma "auto_vacuum", mode, AUTO_VACUUM_MODES
    end

automatic_index() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 120
    def automatic_index
      get_boolean_pragma "automatic_index"
    end

automatic_index=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 124
    def automatic_index=( mode )
      set_boolean_pragma "automatic_index", mode
    end

busy_timeout() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 128
    def busy_timeout
      get_int_pragma "busy_timeout"
    end

busy_timeout=( milliseconds ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 132
    def busy_timeout=( milliseconds )
      set_int_pragma "busy_timeout", milliseconds
    end

cache_size() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 136
    def cache_size
      get_int_pragma "cache_size"
    end

cache_size=( size ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 140
    def cache_size=( size )
      set_int_pragma "cache_size", size
    end

cache_spill() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 144
    def cache_spill
      get_boolean_pragma "cache_spill"
    end

cache_spill=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 148
    def cache_spill=( mode )
      set_boolean_pragma "cache_spill", mode
    end

case_sensitive_like=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 152
    def case_sensitive_like=( mode )
      set_boolean_pragma "case_sensitive_like", mode
    end

cell_size_check() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 156
    def cell_size_check
      get_boolean_pragma "cell_size_check"
    end

cell_size_check=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 160
    def cell_size_check=( mode )
      set_boolean_pragma "cell_size_check", mode
    end

checkpoint_fullfsync() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 164
    def checkpoint_fullfsync
      get_boolean_pragma "checkpoint_fullfsync"
    end

checkpoint_fullfsync=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 168
    def checkpoint_fullfsync=( mode )
      set_boolean_pragma "checkpoint_fullfsync", mode
    end

collation_list( ) { |row| ... } click to toggle source

    # File lib/sqlite3/pragmas.rb, line 172
    def collation_list( &block ) # :yields: row
      get_query_pragma "collation_list", &block
    end

compile_options( ) { |row| ... } click to toggle source

    # File lib/sqlite3/pragmas.rb, line 176
    def compile_options( &block ) # :yields: row
      get_query_pragma "compile_options", &block
    end

count_changes() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 180
    def count_changes
      get_boolean_pragma "count_changes"
    end

count_changes=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 184
    def count_changes=( mode )
      set_boolean_pragma "count_changes", mode
    end

data_version() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 188
    def data_version
      get_int_pragma "data_version"
    end

database_list( ) { |row| ... } click to toggle source

    # File lib/sqlite3/pragmas.rb, line 192
    def database_list( &block ) # :yields: row
      get_query_pragma "database_list", &block
    end

default_cache_size() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 196
    def default_cache_size
      get_int_pragma "default_cache_size"
    end

default_cache_size=( size ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 200
    def default_cache_size=( size )
      set_int_pragma "default_cache_size", size
    end

default_synchronous() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 204
    def default_synchronous
      get_enum_pragma "default_synchronous"
    end

default_synchronous=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 208
    def default_synchronous=( mode )
      set_enum_pragma "default_synchronous", mode, SYNCHRONOUS_MODES
    end

default_temp_store() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 212
    def default_temp_store
      get_enum_pragma "default_temp_store"
    end

default_temp_store=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 216
    def default_temp_store=( mode )
      set_enum_pragma "default_temp_store", mode, TEMP_STORE_MODES
    end

defer_foreign_keys() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 220
    def defer_foreign_keys
      get_boolean_pragma "defer_foreign_keys"
    end

defer_foreign_keys=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 224
    def defer_foreign_keys=( mode )
      set_boolean_pragma "defer_foreign_keys", mode
    end

encoding() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 228
    def encoding
      get_enum_pragma "encoding"
    end

encoding=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 232
    def encoding=( mode )
      set_enum_pragma "encoding", mode, ENCODINGS
    end

foreign_key_check( *table ) { |row| ... } click to toggle source

    # File lib/sqlite3/pragmas.rb, line 236
    def foreign_key_check( *table, &block ) # :yields: row
      get_query_pragma "foreign_key_check", *table, &block
    end

foreign_key_list( table ) { |row| ... } click to toggle source

    # File lib/sqlite3/pragmas.rb, line 240
    def foreign_key_list( table, &block ) # :yields: row
      get_query_pragma "foreign_key_list", table, &block
    end

foreign_keys() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 244
    def foreign_keys
      get_boolean_pragma "foreign_keys"
    end

foreign_keys=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 248
    def foreign_keys=( mode )
      set_boolean_pragma "foreign_keys", mode
    end

freelist_count() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 252
    def freelist_count
      get_int_pragma "freelist_count"
    end

full_column_names() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 256
    def full_column_names
      get_boolean_pragma "full_column_names"
    end

full_column_names=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 260
    def full_column_names=( mode )
      set_boolean_pragma "full_column_names", mode
    end

fullfsync() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 264
    def fullfsync
      get_boolean_pragma "fullfsync"
    end

fullfsync=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 268
    def fullfsync=( mode )
      set_boolean_pragma "fullfsync", mode
    end

get_boolean_pragma( name ) click to toggle source

Returns `true` or `false` depending on the value of the named pragma.

    # File lib/sqlite3/pragmas.rb, line 13
    def get_boolean_pragma( name )
      get_first_value( "PRAGMA #{name}" ) != "0"
    end

get_enum_pragma( name ) click to toggle source

Return the value of the given pragma.

    # File lib/sqlite3/pragmas.rb, line 55
    def get_enum_pragma( name )
      get_first_value( "PRAGMA #{name}" )
    end

get_int_pragma( name ) click to toggle source

Returns the value of the given pragma as an integer.

    # File lib/sqlite3/pragmas.rb, line 72
    def get_int_pragma( name )
      get_first_value( "PRAGMA #{name}" ).to_i
    end

get_query_pragma( name, *parms ) { |row| ... } click to toggle source

Requests the given pragma (and parameters), and if the block is given, each row of the result set will be yielded to it. Otherwise, the results are returned as an array.

    # File lib/sqlite3/pragmas.rb, line 45
    def get_query_pragma( name, *parms, &block ) # :yields: row
      if parms.empty?
        execute( "PRAGMA #{name}", &block )
      else
        args = "'" + parms.join("','") + "'"
        execute( "PRAGMA #{name}( #{args} )", &block )
      end
    end

ignore_check_constraints=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 272
    def ignore_check_constraints=( mode )
      set_boolean_pragma "ignore_check_constraints", mode
    end

incremental_vacuum( pages ) { |row| ... } click to toggle source

    # File lib/sqlite3/pragmas.rb, line 276
    def incremental_vacuum( pages, &block ) # :yields: row
      get_query_pragma "incremental_vacuum", pages, &block
    end

index_info( index ) { |row| ... } click to toggle source

    # File lib/sqlite3/pragmas.rb, line 280
    def index_info( index, &block ) # :yields: row
      get_query_pragma "index_info", index, &block
    end

index_list( table ) { |row| ... } click to toggle source

    # File lib/sqlite3/pragmas.rb, line 284
    def index_list( table, &block ) # :yields: row
      get_query_pragma "index_list", table, &block
    end

index_xinfo( index ) { |row| ... } click to toggle source

    # File lib/sqlite3/pragmas.rb, line 288
    def index_xinfo( index, &block ) # :yields: row
      get_query_pragma "index_xinfo", index, &block
    end

integrity_check( *num_errors ) { |row| ... } click to toggle source

    # File lib/sqlite3/pragmas.rb, line 292
    def integrity_check( *num_errors, &block ) # :yields: row
      get_query_pragma "integrity_check", *num_errors, &block
    end

journal_mode() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 296
    def journal_mode
      get_enum_pragma "journal_mode"
    end

journal_mode=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 300
    def journal_mode=( mode )
      set_enum_pragma "journal_mode", mode, JOURNAL_MODES
    end

journal_size_limit() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 304
    def journal_size_limit
      get_int_pragma "journal_size_limit"
    end

journal_size_limit=( size ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 308
    def journal_size_limit=( size )
      set_int_pragma "journal_size_limit", size
    end

legacy_file_format() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 312
    def legacy_file_format
      get_boolean_pragma "legacy_file_format"
    end

legacy_file_format=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 316
    def legacy_file_format=( mode )
      set_boolean_pragma "legacy_file_format", mode
    end

locking_mode() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 320
    def locking_mode
      get_enum_pragma "locking_mode"
    end

locking_mode=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 324
    def locking_mode=( mode )
      set_enum_pragma "locking_mode", mode, LOCKING_MODES
    end

max_page_count() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 328
    def max_page_count
      get_int_pragma "max_page_count"
    end

max_page_count=( size ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 332
    def max_page_count=( size )
      set_int_pragma "max_page_count", size
    end

mmap_size() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 336
    def mmap_size
      get_int_pragma "mmap_size"
    end

mmap_size=( size ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 340
    def mmap_size=( size )
      set_int_pragma "mmap_size", size
    end

page_count() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 344
    def page_count
      get_int_pragma "page_count"
    end

page_size() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 348
    def page_size
      get_int_pragma "page_size"
    end

page_size=( size ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 352
    def page_size=( size )
      set_int_pragma "page_size", size
    end

parser_trace=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 356
    def parser_trace=( mode )
      set_boolean_pragma "parser_trace", mode
    end

query_only() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 360
    def query_only
      get_boolean_pragma "query_only"
    end

query_only=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 364
    def query_only=( mode )
      set_boolean_pragma "query_only", mode
    end

quick_check( *num_errors ) { |row| ... } click to toggle source

    # File lib/sqlite3/pragmas.rb, line 368
    def quick_check( *num_errors, &block ) # :yields: row
      get_query_pragma "quick_check", *num_errors, &block
    end

read_uncommitted() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 372
    def read_uncommitted
      get_boolean_pragma "read_uncommitted"
    end

read_uncommitted=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 376
    def read_uncommitted=( mode )
      set_boolean_pragma "read_uncommitted", mode
    end

recursive_triggers() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 380
    def recursive_triggers
      get_boolean_pragma "recursive_triggers"
    end

recursive_triggers=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 384
    def recursive_triggers=( mode )
      set_boolean_pragma "recursive_triggers", mode
    end

reverse_unordered_selects() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 388
    def reverse_unordered_selects
      get_boolean_pragma "reverse_unordered_selects"
    end

reverse_unordered_selects=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 392
    def reverse_unordered_selects=( mode )
      set_boolean_pragma "reverse_unordered_selects", mode
    end

schema_cookie() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 396
    def schema_cookie
      get_int_pragma "schema_cookie"
    end

schema_cookie=( cookie ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 400
    def schema_cookie=( cookie )
      set_int_pragma "schema_cookie", cookie
    end

schema_version() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 404
    def schema_version
      get_int_pragma "schema_version"
    end

schema_version=( version ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 408
    def schema_version=( version )
      set_int_pragma "schema_version", version
    end

secure_delete() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 412
    def secure_delete
      get_boolean_pragma "secure_delete"
    end

secure_delete=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 416
    def secure_delete=( mode )
      set_boolean_pragma "secure_delete", mode
    end

set_boolean_pragma( name, mode ) click to toggle source

Sets the given pragma to the given boolean value. The value itself may be `true` or `false`, or any other commonly used string or integer that represents truth.

    # File lib/sqlite3/pragmas.rb, line 20
    def set_boolean_pragma( name, mode )
      case mode
        when String
          case mode.downcase
            when "on", "yes", "true", "y", "t"; mode = "'ON'"
            when "off", "no", "false", "n", "f"; mode = "'OFF'"
            else
              raise Exception,
                "unrecognized pragma parameter #{mode.inspect}"
          end
        when true, 1
          mode = "ON"
        when false, 0, nil
          mode = "OFF"
        else
          raise Exception,
            "unrecognized pragma parameter #{mode.inspect}"
      end

      execute( "PRAGMA #{name}=#{mode}" )
    end

set_enum_pragma( name, mode, enums ) click to toggle source

Set the value of the given pragma to `mode`. The `mode` parameter must conform to one of the values in the given `enum` array. Each entry in the array is another array comprised of elements in the enumeration that have duplicate values. See synchronous, default_synchronous, temp_store, and default_temp_store for usage examples.

    # File lib/sqlite3/pragmas.rb, line 64
    def set_enum_pragma( name, mode, enums )
      match = enums.find { |p| p.find { |i| i.to_s.downcase == mode.to_s.downcase } }
      raise Exception,
        "unrecognized #{name} #{mode.inspect}" unless match
      execute( "PRAGMA #{name}='#{match.first.upcase}'" )
    end

set_int_pragma( name, value ) click to toggle source

Set the value of the given pragma to the integer value of the `value` parameter.

    # File lib/sqlite3/pragmas.rb, line 78
    def set_int_pragma( name, value )
      execute( "PRAGMA #{name}=#{value.to_i}" )
    end

short_column_names() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 420
    def short_column_names
      get_boolean_pragma "short_column_names"
    end

short_column_names=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 424
    def short_column_names=( mode )
      set_boolean_pragma "short_column_names", mode
    end

shrink_memory() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 428
    def shrink_memory
      execute( "PRAGMA shrink_memory" )
    end

soft_heap_limit() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 432
    def soft_heap_limit
      get_int_pragma "soft_heap_limit"
    end

soft_heap_limit=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 436
    def soft_heap_limit=( mode )
      set_int_pragma "soft_heap_limit", mode
    end

stats( ) { |row| ... } click to toggle source

    # File lib/sqlite3/pragmas.rb, line 440
    def stats( &block ) # :yields: row
      get_query_pragma "stats", &block
    end

synchronous() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 444
    def synchronous
      get_enum_pragma "synchronous"
    end

synchronous=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 448
    def synchronous=( mode )
      set_enum_pragma "synchronous", mode, SYNCHRONOUS_MODES
    end

table_info(table) { |new_row| ... } click to toggle source

Returns information about `table`. Yields each row of table information if a block is provided.

    # File lib/sqlite3/pragmas.rb, line 527
    def table_info table
      stmt    = prepare "PRAGMA table_info(#{table})"
      columns = stmt.columns

      needs_tweak_default =
        version_compare(SQLite3.libversion.to_s, "3.3.7") > 0

      result = [] unless block_given?
      stmt.each do |row|
        new_row = Hash[columns.zip(row)]

        # FIXME: This should be removed but is required for older versions
        # of rails
        if(Object.const_defined?(:ActiveRecord))
          new_row['notnull'] = new_row['notnull'].to_s
        end

        tweak_default(new_row) if needs_tweak_default

        if block_given?
          yield new_row
        else
          result << new_row
        end
      end
      stmt.close

      result
    end

temp_store() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 452
    def temp_store
      get_enum_pragma "temp_store"
    end

temp_store=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 456
    def temp_store=( mode )
      set_enum_pragma "temp_store", mode, TEMP_STORE_MODES
    end

threads() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 460
    def threads
      get_int_pragma "threads"
    end

threads=( count ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 464
    def threads=( count )
      set_int_pragma "threads", count
    end

user_cookie() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 468
    def user_cookie
      get_int_pragma "user_cookie"
    end

user_cookie=( cookie ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 472
    def user_cookie=( cookie )
      set_int_pragma "user_cookie", cookie
    end

user_version() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 476
    def user_version
      get_int_pragma "user_version"
    end

user_version=( version ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 480
    def user_version=( version )
      set_int_pragma "user_version", version
    end

vdbe_addoptrace=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 484
    def vdbe_addoptrace=( mode )
      set_boolean_pragma "vdbe_addoptrace", mode
    end

vdbe_debug=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 488
    def vdbe_debug=( mode )
      set_boolean_pragma "vdbe_debug", mode
    end

vdbe_listing=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 492
    def vdbe_listing=( mode )
      set_boolean_pragma "vdbe_listing", mode
    end

vdbe_trace() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 496
    def vdbe_trace
      get_boolean_pragma "vdbe_trace"
    end

vdbe_trace=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 500
    def vdbe_trace=( mode )
      set_boolean_pragma "vdbe_trace", mode
    end

wal_autocheckpoint() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 504
    def wal_autocheckpoint
      get_int_pragma "wal_autocheckpoint"
    end

wal_autocheckpoint=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 508
    def wal_autocheckpoint=( mode )
      set_int_pragma "wal_autocheckpoint", mode
    end

wal_checkpoint() click to toggle source

    # File lib/sqlite3/pragmas.rb, line 512
    def wal_checkpoint
      get_enum_pragma "wal_checkpoint"
    end

wal_checkpoint=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 516
    def wal_checkpoint=( mode )
      set_enum_pragma "wal_checkpoint", mode, WAL_CHECKPOINTS
    end

writable_schema=( mode ) click to toggle source

    # File lib/sqlite3/pragmas.rb, line 520
    def writable_schema=( mode )
      set_boolean_pragma "writable_schema", mode
    end

### Private Instance Methods

tweak_default(hash) click to toggle source

Since SQLite 3.3.8, the #table_info pragma has returned the default value of the row as a quoted SQL value. This method essentially unquotes those values.

    # File lib/sqlite3/pragmas.rb, line 576
    def tweak_default(hash)
      case hash["dflt_value"]
      when /^null$/i
        hash["dflt_value"] = nil
      when /^'(.*)'$/m
        hash["dflt_value"] = $1.gsub(/''/, "'")
      when /^"(.*)"$/m
        hash["dflt_value"] = $1.gsub(/""/, '"')
      end
    end

version_compare(v1, v2) click to toggle source

Compares two version strings

    # File lib/sqlite3/pragmas.rb, line 560
    def version_compare(v1, v2)
      v1 = v1.split(".").map { |i| i.to_i }
      v2 = v2.split(".").map { |i| i.to_i }
      parts = [v1.length, v2.length].max
      v1.push 0 while v1.length < parts
      v2.push 0 while v2.length < parts
      v1.zip(v2).each do |a,b|
        return -1 if a < b
        return  1 if a > b
      end
      return 0
    end