Class: ActiveRecord::ConnectionAdapters::SQLiteAdapter

Inherits:
AbstractAdapter show all
Defined in:
lib/active_record/connection_adapters/sqlite_adapter.rb

Overview

The SQLite adapter works with both the 2.x and 3.x series of SQLite with the sqlite-ruby drivers (available both as gems and from rubyforge.org/projects/sqlite-ruby/).

Options:

  • :database - Path to the database file.

Direct Known Subclasses

SQLite3Adapter

Defined Under Namespace

Classes: BindSubstitution, ExplainPrettyPrinter, StatementPool, Version

Instance Attribute Summary

Attributes inherited from AbstractAdapter

#in_use, #last_use, #logger, #open_transactions, #pool, #schema_cache, #visitor

Attributes included from QueryCache

#query_cache, #query_cache_enabled

Instance Method Summary collapse

Methods inherited from AbstractAdapter

#active?, #case_insensitive_comparison, #case_sensitive_modifier, #close, #current_savepoint_name, #decrement_open_transactions, #disable_referential_integrity, #expire, #increment_open_transactions, #lease, #prefetch_primary_key?, #quote_table_name, #raw_connection, #reconnect!, #reset!, #substitute_at, #supports_bulk_alter?, #transaction_joinable=, #verify!

Methods included from QueryCache

#cache, #clear_query_cache, dirties_query_cache, #disable_query_cache!, #enable_query_cache!, included, #select_all, #uncached

Methods included from DatabaseLimits

#column_name_length, #columns_per_multicolumn_index, #columns_per_table, #in_clause_length, #index_name_length, #indexes_per_table, #joins_per_query, #sql_query_length, #table_alias_length, #table_name_length

Methods included from Quoting

#quote, #quote_table_name, #quoted_false, #quoted_true

Methods included from DatabaseStatements

#add_transaction_record, #case_sensitive_equality_operator, #default_sequence_name, #delete, #exec_insert, #insert, #insert_fixture, #join_to_update, #limited_update_conditions, #outside_transaction?, #reset_sequence!, #sanitize_limit, #select_all, #select_one, #select_value, #select_values, #to_sql, #transaction, #update

Methods included from SchemaStatements

#add_column_options!, #add_index, #add_timestamps, #assume_migrated_upto_version, #change_table, #column_exists?, #create_table, #distinct, #drop_table, #dump_schema_information, #index_exists?, #index_name, #index_name_exists?, #initialize_schema_migrations_table, #remove_index, #remove_timestamps, #rename_index, #structure_dump, #table_alias_for, #type_to_sql

Constructor Details

#initialize(connection, logger, config) ⇒ SQLiteAdapter

Returns a new instance of SQLiteAdapter.



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 77

def initialize(connection, logger, config)
  super(connection, logger)
  @statements = StatementPool.new(@connection,
                                  config.fetch(:statement_limit) { 1000 })
  @config = config

  if config.fetch(:prepared_statements) { true }
    @visitor = Arel::Visitors::SQLite.new self
  else
    @visitor = BindSubstitution.new self
  end
end

Instance Method Details

#adapter_nameObject

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 90

def adapter_name #:nodoc:
  'SQLite'
end

#add_column(table_name, column_name, type, options = {}) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 398

def add_column(table_name, column_name, type, options = {}) #:nodoc:
  if supports_add_column? && valid_alter_table_options( type, options )
    super(table_name, column_name, type, options)
  else
    alter_table(table_name) do |definition|
      definition.column(column_name, type, options)
    end
  end
end

#begin_db_transactionObject

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 313

def begin_db_transaction #:nodoc:
  log('begin transaction',nil) { @connection.transaction }
end

#change_column(table_name, column_name, type, options = {}) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 440

def change_column(table_name, column_name, type, options = {}) #:nodoc:
  alter_table(table_name) do |definition|
    include_default = options_include_default?(options)
    definition[column_name].instance_eval do
      self.type    = type
      self.limit   = options[:limit] if options.include?(:limit)
      self.default = options[:default] if include_default
      self.null    = options[:null] if options.include?(:null)
      self.precision = options[:precision] if options.include?(:precision)
      self.scale   = options[:scale] if options.include?(:scale)
    end
  end
end

#change_column_default(table_name, column_name, default) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 425

def change_column_default(table_name, column_name, default) #:nodoc:
  alter_table(table_name) do |definition|
    definition[column_name].default = default
  end
end

#change_column_null(table_name, column_name, null, default = nil) ⇒ Object



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 431

def change_column_null(table_name, column_name, null, default = nil)
  unless null || default.nil?
    exec_query("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
  end
  alter_table(table_name) do |definition|
    definition[column_name].null = null
  end
end

#clear_cache!Object

Clears the prepared statements cache.



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 143

def clear_cache!
  @statements.clear
end

#columns(table_name, name = nil) ⇒ Object

Returns an array of SQLiteColumn objects for the table specified by table_name.



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 345

def columns(table_name, name = nil) #:nodoc:
  table_structure(table_name).map do |field|
    case field["dflt_value"]
    when /^null$/i
      field["dflt_value"] = nil
    when /^'(.*)'$/
      field["dflt_value"] = $1.gsub(/''/, "'")
    when /^"(.*)"$/
      field["dflt_value"] = $1.gsub(/""/, '"')
    end

    SQLiteColumn.new(field['name'], field['dflt_value'], field['type'], field['notnull'].to_i == 0)
  end
end

#commit_db_transactionObject

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 317

def commit_db_transaction #:nodoc:
  log('commit transaction',nil) { @connection.commit }
end

#create_savepointObject



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 301

def create_savepoint
  execute("SAVEPOINT #{current_savepoint_name}")
end

#delete_sql(sql, name = nil) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 286

def delete_sql(sql, name = nil) #:nodoc:
  sql += " WHERE 1=1" unless sql =~ /WHERE/i
  super sql, name
end

#disconnect!Object

Disconnects from the database if already connected. Otherwise, this method does nothing.



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 136

def disconnect!
  super
  clear_cache!
  @connection.close rescue nil
end

#empty_insert_statement_valueObject



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 461

def empty_insert_statement_value
  "VALUES(NULL)"
end

#exec_delete(sql, name = 'SQL', binds = []) ⇒ Object Also known as: exec_update



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 267

def exec_delete(sql, name = 'SQL', binds = [])
  exec_query(sql, name, binds)
  @connection.changes
end

#exec_query(sql, name = nil, binds = []) ⇒ Object



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 241

def exec_query(sql, name = nil, binds = [])
  log(sql, name, binds) do

    # Don't cache statements without bind values
    if binds.empty?
      stmt    = @connection.prepare(sql)
      cols    = stmt.columns
      records = stmt.to_a
      stmt.close
      stmt = records
    else
      cache = @statements[sql] ||= {
        :stmt => @connection.prepare(sql)
      }
      stmt = cache[:stmt]
      cols = cache[:cols] ||= stmt.columns
      stmt.reset!
      stmt.bind_params binds.map { |col, val|
        type_cast(val, col)
      }
    end

    ActiveRecord::Result.new(cols, stmt.to_a)
  end
end

#execute(sql, name = nil) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 277

def execute(sql, name = nil) #:nodoc:
  log(sql, name) { @connection.execute(sql) }
end

#explain(arel, binds = []) ⇒ Object

DATABASE STATEMENTS ======================================



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 222

def explain(arel, binds = [])
  sql = "EXPLAIN QUERY PLAN #{to_sql(arel, binds)}"
  ExplainPrettyPrinter.new.pp(exec_query(sql, 'EXPLAIN', binds))
end

#indexes(table_name, name = nil) ⇒ Object

Returns an array of indexes for the given table.



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 361

def indexes(table_name, name = nil) #:nodoc:
  exec_query("PRAGMA index_list(#{quote_table_name(table_name)})", 'SCHEMA').map do |row|
    IndexDefinition.new(
      table_name,
      row['name'],
      row['unique'] != 0,
      exec_query("PRAGMA index_info('#{row['name']}')", 'SCHEMA').map { |col|
        col['name']
      })
  end
end

#insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) ⇒ Object Also known as: create

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 291

def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) #:nodoc:
  super
  id_value || @connection.last_insert_row_id
end

#last_inserted_id(result) ⇒ Object



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 273

def last_inserted_id(result)
  @connection.last_insert_row_id
end

#native_database_typesObject

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 161

def native_database_types #:nodoc:
  {
    :primary_key => default_primary_key_type,
    :string      => { :name => "varchar", :limit => 255 },
    :text        => { :name => "text" },
    :integer     => { :name => "integer" },
    :float       => { :name => "float" },
    :decimal     => { :name => "decimal" },
    :datetime    => { :name => "datetime" },
    :timestamp   => { :name => "datetime" },
    :time        => { :name => "time" },
    :date        => { :name => "date" },
    :binary      => { :name => "blob" },
    :boolean     => { :name => "boolean" }
  }
end

#primary_key(table_name) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 373

def primary_key(table_name) #:nodoc:
  column = table_structure(table_name).find { |field|
    field['pk'] == 1
  }
  column && column['name']
end

#quote_column_name(name) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 185

def quote_column_name(name) #:nodoc:
  %Q("#{name.to_s.gsub('"', '""')}")
end

#quote_string(s) ⇒ Object

QUOTING ==================================================



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 181

def quote_string(s) #:nodoc:
  @connection.class.quote(s)
end

#quoted_date(value) ⇒ Object

Quote date/time values for use in SQL input. Includes microseconds if the value is a Time responding to usec.



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 191

def quoted_date(value) #:nodoc:
  if value.respond_to?(:usec)
    "#{super}.#{sprintf("%06d", value.usec)}"
  else
    super
  end
end

#release_savepointObject



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 309

def release_savepoint
  execute("RELEASE SAVEPOINT #{current_savepoint_name}")
end

#remove_column(table_name, *column_names) ⇒ Object Also known as: remove_columns

:nodoc:

Raises:

  • (ArgumentError)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 408

def remove_column(table_name, *column_names) #:nodoc:
  raise ArgumentError.new("You must specify at least one column name. Example: remove_column(:people, :first_name)") if column_names.empty?

  if column_names.flatten!
    message = 'Passing array to remove_columns is deprecated, please use ' +
              'multiple arguments, like: `remove_columns(:posts, :foo, :bar)`'
    ActiveSupport::Deprecation.warn message, caller
  end

  column_names.each do |column_name|
    alter_table(table_name) do |definition|
      definition.columns.delete(definition[column_name])
    end
  end
end

#remove_index!(table_name, index_name) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 380

def remove_index!(table_name, index_name) #:nodoc:
  exec_query "DROP INDEX #{quote_column_name(index_name)}"
end

#rename_column(table_name, column_name, new_column_name) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 454

def rename_column(table_name, column_name, new_column_name) #:nodoc:
  unless columns(table_name).detect{|c| c.name == column_name.to_s }
    raise ActiveRecord::ActiveRecordError, "Missing column #{table_name}.#{column_name}"
  end
  alter_table(table_name, :rename => {column_name.to_s => new_column_name.to_s})
end

#rename_table(name, new_name) ⇒ Object

Renames a table.

Example:

rename_table('octopuses', 'octopi')


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 388

def rename_table(name, new_name)
  exec_query "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}"
end

#requires_reloading?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 125

def requires_reloading?
  true
end

#rollback_db_transactionObject

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 321

def rollback_db_transaction #:nodoc:
  log('rollback transaction',nil) { @connection.rollback }
end

#rollback_to_savepointObject



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 305

def rollback_to_savepoint
  execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
end

#select_rows(sql, name = nil) ⇒ Object



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 297

def select_rows(sql, name = nil)
  exec_query(sql, name).rows
end

#supports_add_column?Boolean

Returns true if SQLite version is ‘3.1.6’ or greater, false otherwise.

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 130

def supports_add_column?
  sqlite_version >= '3.1.6'
end

#supports_autoincrement?Boolean

Returns true if SQLite version is ‘3.1.0’ or greater, false otherwise.

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 153

def supports_autoincrement? #:nodoc:
  sqlite_version >= '3.1.0'
end

#supports_count_distinct?Boolean

Returns true if SQLite version is ‘3.2.6’ or greater, false otherwise.

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 148

def supports_count_distinct? #:nodoc:
  sqlite_version >= '3.2.6'
end

#supports_ddl_transactions?Boolean

Returns true if SQLite version is ‘2.0.0’ or greater, false otherwise.

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 95

def supports_ddl_transactions?
  sqlite_version >= '2.0.0'
end

#supports_explain?Boolean

Returns true.

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 121

def supports_explain?
  true
end

#supports_index_sort_order?Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 157

def supports_index_sort_order?
  sqlite_version >= '3.3.0'
end

#supports_migrations?Boolean

Returns true, since this connection adapter supports migrations.

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 111

def supports_migrations? #:nodoc:
  true
end

#supports_primary_key?Boolean

Returns true.

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 116

def supports_primary_key? #:nodoc:
  true
end

#supports_savepoints?Boolean

Returns true if SQLite version is ‘3.6.8’ or greater, false otherwise.

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 100

def supports_savepoints?
  sqlite_version >= '3.6.8'
end

#supports_statement_cache?Boolean

Returns true, since this connection adapter supports prepared statement caching.

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 106

def supports_statement_cache?
  true
end

#table_exists?(name) ⇒ Boolean

Returns:

  • (Boolean)


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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 340

def table_exists?(name)
  name && tables('SCHEMA', name).any?
end

#tables(name = 'SCHEMA', table_name = nil) ⇒ Object

SCHEMA STATEMENTS ========================================



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 327

def tables(name = 'SCHEMA', table_name = nil) #:nodoc:
  sql = <<-SQL
    SELECT name
    FROM sqlite_master
    WHERE type = 'table' AND NOT name = 'sqlite_sequence'
  SQL
  sql << " AND name = #{quote_table_name(table_name)}" if table_name

  exec_query(sql, name).map do |row|
    row['name']
  end
end

#type_cast(value, column) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 200

def type_cast(value, column) # :nodoc:
  return value.to_f if BigDecimal === value
  return super unless String === value
  return super unless column && value

  value = super
  if column.type == :string && value.encoding == Encoding::ASCII_8BIT
    logger.error "Binary data inserted for `string` type on column `#{column.name}`" if logger
    value = value.encode Encoding::UTF_8
  end
  value
end

#update_sql(sql, name = nil) ⇒ Object

:nodoc:



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 281

def update_sql(sql, name = nil) #:nodoc:
  super
  @connection.changes
end

#valid_alter_table_options(type, options) ⇒ Object

See: www.sqlite.org/lang_altertable.html SQLite has an additional restriction on the ALTER TABLE statement



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# File 'lib/active_record/connection_adapters/sqlite_adapter.rb', line 394

def valid_alter_table_options( type, options)
  type.to_sym != :primary_key
end