Module: Sequel::SQLite::DatabaseMethods

Included in:
Amalgalite::Database, DataObjects::SQLite::DatabaseMethods, JDBC::SQLite::DatabaseMethods, Database, Sequel::Swift::SQLite::DatabaseMethods
Defined in:
lib/sequel/adapters/shared/sqlite.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
PRIMARY_KEY_INDEX_RE = 
/\Asqlite_autoindex_/.freeze
SYNCHRONOUS = 
[:off, :normal, :full].freeze
TABLES_FILTER = 
"type = 'table' AND NOT name = 'sqlite_sequence'"
TEMP_STORE = 
[:default, :file, :memory].freeze

Instance Method Summary collapse

Instance Method Details

#alter_table(name, generator = nil, &block) ⇒ Object

Run all alter_table commands in a transaction. This is technically only needed for drop column.



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# File 'lib/sequel/adapters/shared/sqlite.rb', line 15

def alter_table(name, generator=nil, &block)
  remove_cached_schema(name)
  generator ||= Schema::AlterTableGenerator.new(self, &block)
  transaction{generator.operations.each{|op| alter_table_sql_list(name, [op]).flatten.each{|sql| execute_ddl(sql)}}}
end

#auto_vacuum ⇒ Object

A symbol signifying the value of the auto_vacuum PRAGMA.



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# File 'lib/sequel/adapters/shared/sqlite.rb', line 22

def auto_vacuum
  AUTO_VACUUM[pragma_get(:auto_vacuum).to_i]
end

#auto_vacuum=(value) ⇒ Object

Set the auto_vacuum PRAGMA using the given symbol (:none, :full, or :incremental). See pragma_set. Consider using the :auto_vacuum Database option instead.



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# File 'lib/sequel/adapters/shared/sqlite.rb', line 29

def auto_vacuum=(value)
  value = AUTO_VACUUM.index(value) || (raise Error, "Invalid value for auto_vacuum option. Please specify one of :none, :full, :incremental.")
  pragma_set(:auto_vacuum, value)
end

#database_type ⇒ Object

SQLite uses the :sqlite database type.



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# File 'lib/sequel/adapters/shared/sqlite.rb', line 35

def database_type
  :sqlite
end

#foreign_keys ⇒ Object

Boolean signifying the value of the foreign_keys PRAGMA, or nil if not using SQLite 3.6.19+.



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# File 'lib/sequel/adapters/shared/sqlite.rb', line 41

def foreign_keys
  pragma_get(:foreign_keys).to_i == 1 if sqlite_version >= 30619
end

#foreign_keys=(value) ⇒ Object

Set the foreign_keys PRAGMA using the given boolean value, if using SQLite 3.6.19+. If not using 3.6.19+, no error is raised. See pragma_set. Consider using the :foreign_keys Database option instead.



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# File 'lib/sequel/adapters/shared/sqlite.rb', line 48

def foreign_keys=(value)
  pragma_set(:foreign_keys, !!value ? 'on' : 'off') if sqlite_version >= 30619
end

#indexes(table, 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/sqlite.rb', line 53

def indexes(table, opts={})
  m = output_identifier_meth
  im = input_identifier_meth
  indexes = {}
  begin
    metadata_dataset.with_sql("PRAGMA index_list(?)", im.call(table)).each do |r|
      next if r[:name] =~ PRIMARY_KEY_INDEX_RE
      indexes[m.call(r[:name])] = {:unique=>r[:unique].to_i==1}
    end
  rescue Sequel::DatabaseError
    nil
  else
    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
  end
  indexes
end

#pragma_get(name) ⇒ Object

Get the value of the given PRAGMA.



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# File 'lib/sequel/adapters/shared/sqlite.rb', line 73

def pragma_get(name)
  self["PRAGMA #{name}"].single_value
end

#pragma_set(name, value) ⇒ Object

Set the value of the given PRAGMA to value.

This method is not thread safe, and will not work correctly if there are multiple connections in the Database’s connection pool. PRAGMA modifications should be done when the connection is created, using an option provided when creating the Database object.



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

def pragma_set(name, value)
  execute_ddl("PRAGMA #{name} = #{value}")
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/sqlite.rb', line 89

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

#supports_savepoints? ⇒ Boolean

SQLite 3.6.8+ supports savepoints.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/sqlite.rb', line 100

def supports_savepoints?
  sqlite_version >= 30608
end

#synchronous ⇒ Object

A symbol signifying the value of the synchronous PRAGMA.



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# File 'lib/sequel/adapters/shared/sqlite.rb', line 105

def synchronous
  SYNCHRONOUS[pragma_get(:synchronous).to_i]
end

#synchronous=(value) ⇒ Object

Set the synchronous PRAGMA using the given symbol (:off, :normal, or :full). See pragma_set. Consider using the :synchronous Database option instead.



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# File 'lib/sequel/adapters/shared/sqlite.rb', line 111

def synchronous=(value)
  value = SYNCHRONOUS.index(value) || (raise Error, "Invalid value for synchronous option. Please specify one of :off, :normal, :full.")
  pragma_set(:synchronous, value)
end

#tables(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/sqlite.rb', line 120

def tables(opts={})
  m = output_identifier_meth
  metadata_dataset.from(:sqlite_master).server(opts[:server]).filter(TABLES_FILTER).map{|r| m.call(r[:name])}
end

#temp_store ⇒ Object

A symbol signifying the value of the temp_store PRAGMA.



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

def temp_store
  TEMP_STORE[pragma_get(:temp_store).to_i]
end

#temp_store=(value) ⇒ Object

Set the temp_store PRAGMA using the given symbol (:default, :file, or :memory). See pragma_set. Consider using the :temp_store Database option instead.



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# File 'lib/sequel/adapters/shared/sqlite.rb', line 132

def temp_store=(value)
  value = TEMP_STORE.index(value) || (raise Error, "Invalid value for temp_store option. Please specify one of :default, :file, :memory.")
  pragma_set(:temp_store, value)
end