Module: Sequel::Litedb::DatabaseMethods

Includes:
UnmodifiedIdentifiers::DatabaseMethods
Defined in:
lib/sequel/adapters/shared/litedb.rb

Overview

No matter how you connect to SQLite, the following Database options can be used to set PRAGMAs on connections in a thread-safe manner: :auto_vacuum, :foreign_keys, :synchronous, and :temp_store.

Constant Summary collapse

AUTO_VACUUM = 
[:none, :full, :incremental].freeze
SYNCHRONOUS = 
[:off, :normal, :full].freeze
TEMP_STORE = 
[:default, :file, :memory].freeze
TRANSACTION_MODE = 
{
  :deferred => "BEGIN DEFERRED TRANSACTION",
  :immediate => "BEGIN IMMEDIATE TRANSACTION",
  :exclusive => "BEGIN EXCLUSIVE TRANSACTION",
  nil => "BEGIN"
}.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#current_timestamp_utc ⇒ Object

Whether to keep CURRENT_TIMESTAMP and similar expressions in UTC. By default, the expressions are converted to localtime.



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# File 'lib/sequel/adapters/shared/litedb.rb', line 43

def current_timestamp_utc
  @current_timestamp_utc
end

#integer_booleans ⇒ Object

Whether to use integers for booleans in the database. SQLite recommends booleans be stored as integers, but historically Sequel has used ‘t’/‘f’.



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# File 'lib/sequel/adapters/shared/litedb.rb', line 39

def integer_booleans
  @integer_booleans
end

#transaction_mode ⇒ Object

A symbol signifying the value of the default transaction mode



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# File 'lib/sequel/adapters/shared/litedb.rb', line 46

def transaction_mode
  @transaction_mode
end

#use_timestamp_timezones=(value) ⇒ Object (writeonly)

Override the default setting for whether to use timezones in timestamps. It is set to false by default, as SQLite’s date/time methods do not support timezones in timestamps.



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# File 'lib/sequel/adapters/shared/litedb.rb', line 151

def use_timestamp_timezones=(value)
  @use_timestamp_timezones = value
end

Instance Method Details

#database_type ⇒ Object

SQLite uses the :sqlite database type.



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# File 'lib/sequel/adapters/shared/litedb.rb', line 58

def database_type
  :litedb
end

#foreign_key_list(table, opts = OPTS) ⇒ Object

Return the array of foreign key info hashes using the foreign_key_list PRAGMA, including information for the :on_update and :on_delete entries.



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# File 'lib/sequel/adapters/shared/litedb.rb', line 69

def foreign_key_list(table, opts = OPTS)
  m = output_identifier_meth
  h = {}
  _foreign_key_list_ds(table).each do |row|
    if (r = h[row[:id]])
      r[:columns] << m.call(row[:from])
      r[:key] << m.call(row[:to]) if r[:key]
    else
      h[row[:id]] = {columns: [m.call(row[:from])], table: m.call(row[:table]), key: ([m.call(row[:to])] if row[:to]), on_update: on_delete_sql_to_sym(row[:on_update]), on_delete: on_delete_sql_to_sym(row[:on_delete])}
    end
  end
  h.values
end

#freeze ⇒ Object 



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# File 'lib/sequel/adapters/shared/litedb.rb', line 83

def freeze
  sqlite_version
  use_timestamp_timezones?
  super
end

#indexes(table, opts = OPTS) ⇒ Object

Use the index_list and index_info PRAGMAs to determine the indexes on the table.



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# File 'lib/sequel/adapters/shared/litedb.rb', line 90

def indexes(table, opts = OPTS)
  m = output_identifier_meth
  im = input_identifier_meth
  indexes = {}
  table = table.value if table.is_a?(Sequel::SQL::Identifier)
  metadata_dataset.with_sql("PRAGMA index_list(?)", im.call(table)).each do |r|
    if opts[:only_autocreated]
      # If specifically asked for only autocreated indexes, then return those an only those
      next unless r[:name].start_with?("sqlite_autoindex_")
    elsif r.has_key?(:origin)
      # If origin is set, then only exclude primary key indexes and partial indexes
      next if r[:origin] == "pk"
      next if r[:partial].to_i == 1
    elsif r[:name].start_with?("sqlite_autoindex_")
      next
    end
    # When :origin key not present, assume any autoindex could be a primary key one and exclude it

    indexes[m.call(r[:name])] = {unique: r[:unique].to_i == 1}
  end
  indexes.each do |k, v|
    v[:columns] = metadata_dataset.with_sql("PRAGMA index_info(?)", im.call(k)).map(:name).map { |x| m.call(x) }
  end
  indexes
end

#set_integer_booleans ⇒ Object

Set the integer_booleans option using the passed in :integer_boolean option.



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# File 'lib/sequel/adapters/shared/litedb.rb', line 63

def set_integer_booleans
  @integer_booleans = @opts.has_key?(:integer_booleans) ? typecast_value_boolean(@opts[:integer_booleans]) : true
end

#sqlite_version ⇒ Object

The version of the server as an integer, where 3.6.19 = 30619. If the server version can’t be determined, 0 is used.



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# File 'lib/sequel/adapters/shared/litedb.rb', line 118

def sqlite_version
  return @sqlite_version if defined?(@sqlite_version)
  @sqlite_version = begin
    v = fetch("SELECT sqlite_version()").single_value
    [10000, 100, 1].zip(v.split(".")).inject(0) { |a, m| a + m[0] * Integer(m[1]) }
  rescue
    0
  end
end

#supports_create_table_if_not_exists? ⇒ Boolean

SQLite supports CREATE TABLE IF NOT EXISTS syntax since 3.3.0.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/litedb.rb', line 129

def supports_create_table_if_not_exists?
  sqlite_version >= 30300
end

#supports_deferrable_foreign_key_constraints? ⇒ Boolean

SQLite 3.6.19+ supports deferrable foreign key constraints.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/litedb.rb', line 134

def supports_deferrable_foreign_key_constraints?
  sqlite_version >= 30619
end

#supports_partial_indexes? ⇒ Boolean

SQLite 3.8.0+ supports partial indexes.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/litedb.rb', line 139

def supports_partial_indexes?
  sqlite_version >= 30800
end

#supports_savepoints? ⇒ Boolean

SQLite 3.6.8+ supports savepoints.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/litedb.rb', line 144

def supports_savepoints?
  sqlite_version >= 30608
end

#tables(opts = OPTS) ⇒ Object

Array of symbols specifying the table names in the current database.

Options:

:server

Set the server to use.



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# File 'lib/sequel/adapters/shared/litedb.rb', line 163

def tables(opts = OPTS)
  tables_and_views(Sequel.~(name: "sqlite_sequence") & {type: "table"}, opts)
end

#use_timestamp_timezones? ⇒ Boolean

SQLite supports timezones in timestamps, since it just stores them as strings, but it breaks the usage of SQLite’s datetime functions.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/litedb.rb', line 155

def use_timestamp_timezones?
  defined?(@use_timestamp_timezones) ? @use_timestamp_timezones : (@use_timestamp_timezones = false)
end

#values(v) ⇒ Object

Creates a dataset that uses the VALUES clause:

DB.values([[1, 2], [3, 4]])
# VALUES ((1, 2), (3, 4))

Raises:

  • (Error) 


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# File 'lib/sequel/adapters/shared/litedb.rb', line 171

def values(v)
  raise Error, "Cannot provide an empty array for values" if v.empty?
  @default_dataset.clone(values: v)
end

#views(opts = OPTS) ⇒ Object

Array of symbols specifying the view names in the current database.

Options:

:server

Set the server to use.



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# File 'lib/sequel/adapters/shared/litedb.rb', line 180

def views(opts = OPTS)
  tables_and_views({type: "view"}, opts)
end