Class: ActiveRecord::ConnectionAdapters::SQLite3Adapter

Relationships & Source Files
Namespace Children
Classes: ExplainPrettyPrinter, StatementPool
Super Chains via Extension / Inclusion / Inheritance
Class Chain: self, AbstractAdapter, ::ActiveSupport::DescendantsTracker
Instance Chain: self, AbstractAdapter, ColumnDumper, MonitorMixin, ::ActiveSupport::Callbacks, ::ActiveRecord::QueryCache, DatabaseLimits, Quoting, DatabaseStatements, SchemaStatements
Inherits:	ActiveRecord::ConnectionAdapters::AbstractAdapter ::Object ActiveRecord::ConnectionAdapters::AbstractAdapter ActiveRecord::ConnectionAdapters::SQLite3Adapter
Defined in:	activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb

Overview

The SQLite3 adapter works SQLite 3.6.16 or newer with the sqlite3-ruby drivers (available as gem from rubygems.org/gems/sqlite3).

Options:

:database - Path to the database file.

Constant Summary

ADAPTER_NAME =
# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 60
```
'SQLite'.freeze
```

NATIVE_DATABASE_TYPES =
# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 63

{
  primary_key:  'INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL',
  string:       { name: "varchar" },
  text:         { name: "text" },
  integer:      { name: "integer" },
  float:        { name: "float" },
  decimal:      { name: "decimal" },
  datetime:     { name: "datetime" },
  time:         { name: "time" },
  date:         { name: "date" },
  binary:       { name: "blob" },
  boolean:      { name: "boolean" }
}

::ActiveSupport::Callbacks - Included

CALLBACK_FILTER_TYPES

AbstractAdapter - Inherited

ADAPTER_NAME, SIMPLE_INT

Class Method Summary

.new(connection, logger, connection_options, config) ⇒ SQLite3Adapter constructor

AbstractAdapter - Inherited

.type_cast_config_to_boolean, .type_cast_config_to_integer

::ActiveSupport::DescendantsTracker - Inherited

clear, descendants, direct_descendants,
store_inherited	This is the only method that is not thread safe, but is only ever called during the eager loading phase.

Instance Attribute Summary

#active? ⇒ Boolean readonly
#requires_reloading? ⇒ Boolean readonly
#supports_ddl_transactions? ⇒ Boolean readonly
#supports_explain? ⇒ Boolean readonly
#supports_index_sort_order? ⇒ Boolean readonly
#supports_partial_index? ⇒ Boolean readonly
#supports_savepoints? ⇒ Boolean readonly
#supports_statement_cache? ⇒ Boolean readonly

Returns true, since this connection adapter supports prepared statement caching.
#supports_views? ⇒ Boolean readonly

AbstractAdapter - Inherited

#active?	Checks whether the connection to the database is still active.
#in_use?	Alias for AbstractAdapter#owner.
#logger, #owner, #pool, #prepared_statements,
#requires_reloading?	Returns true if its required to reload the connection between requests for development mode.
#schema_cache, #schema_cache=, #supports_bulk_alter?,
#supports_ddl_transactions?	Does this adapter support DDL rollbacks in transactions? That is, would CREATE TABLE or ALTER TABLE get rolled back by a transaction?
#supports_explain?	Does this adapter support explain?
#supports_extensions?	Does this adapter support database extensions?
#supports_foreign_keys?	Does this adapter support creating foreign key constraints?
#supports_index_sort_order?	Does this adapter support index sort order?
#supports_indexes_in_create?	Does this adapter support creating indexes in the same statement as creating the table?
#supports_migrations?	Does this adapter support migrations?
#supports_partial_index?	Does this adapter support partial indices?
#supports_primary_key?	Can this adapter determine the primary key for tables not attached to an Active Record class, such as join tables?
#supports_savepoints?	Does this adapter support savepoints?
#supports_transaction_isolation?	Does this adapter support setting the isolation level for a transaction?
#supports_views?	Does this adapter support views?
#visitor

DatabaseStatements - Included

#begin_transaction, #commit_transaction, #current_transaction, #open_transactions, #rollback_transaction,
#supports_statement_cache?	Returns `true` when the connection adapter supports prepared statement caching, otherwise returns `false`
#transaction_open?, #within_new_transaction

Instance Method Summary

#allowed_index_name_length

Returns 62.
#change_column_null(table_name, column_name, null, default = nil)
#clear_cache!

Clears the prepared statements cache.
#create(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)

Alias for #insert_sql.
#data_source_exists?(table_name)

Alias for #table_exists?.
#data_sources(name = nil, table_name = nil)

Alias for #tables.
#disconnect!

Disconnects from the database if already connected.
#encoding

Returns the current database encoding format as a string, eg: 'UTF-8'.
#exec_delete(sql, name = 'SQL', binds = []) (also: #exec_update)
#exec_query(sql, name = nil, binds = [])
#exec_update(sql, name = 'SQL', binds = [])

Alias for #exec_delete.
#explain(arel, binds = [])
#last_inserted_id(result)
#quote_table_name_for_assignment(table, attr)
#rename_table(table_name, new_name)

Renames a table.
#select_rows(sql, name = nil, binds = [])
#table_exists?(table_name) ⇒ Boolean (also: #data_source_exists?)
#valid_alter_table_type?(type) ⇒ Boolean

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

AbstractAdapter - Inherited

#adapter_name	Returns the human-readable name of the adapter.
#case_insensitive_comparison, #case_sensitive_comparison, #case_sensitive_modifier,
#clear_cache!	Clear any caching the database adapter may be doing, for example clearing the prepared statement cache.
#close	Check the connection back in to the connection pool.
#collector, #create_savepoint, #current_savepoint_name,
#disable_extension	This is meant to be implemented by the adapters that support extensions.
#disable_referential_integrity	Override to turn off referential integrity while executing `&block`.
#disconnect!	Disconnects from the database if already connected.
#enable_extension	This is meant to be implemented by the adapters that support extensions.
#expire,
#extensions	A list of extensions, to be filled in by adapters that support them.
#index_algorithms	A list of index algorithms, to be filled by adapters that support them.
#lease, #new_column,
#prefetch_primary_key?	Should primary key values be selected from their corresponding sequence before the insert statement? If true, next_sequence_value is called before each insert to set the record's primary key.
#raw_connection	Provides access to the underlying database driver for this adapter.
#reconnect!	Disconnects from the database if already connected, and establishes a new connection with the database.
#release_savepoint,
#reset!	Reset the state of this connection, directing the DBMS to clear transactions and other connection-related server-side state.
#schema_creation,
#substitute_at	Returns a bind substitution value given a bind `column` NOTE: The column param is currently being used by the sqlserver-adapter.
#unprepared_statement, #valid_type?,
#verify!	Checks whether the connection to the database is still active (i.e. not stale).

ColumnDumper - Included

#column_spec,
#migration_keys	Lists the valid migration options.
#prepare_column_options	This can be overridden on a Adapter level basis to support other extended datatypes (Example: Adding an array option in the PostgreSQLAdapter).

::ActiveSupport::Callbacks - Included

#run_callbacks

Runs the callbacks for the given event.

::ActiveRecord::QueryCache - Included

#call

DatabaseLimits - Included

#allowed_index_name_length	Returns the maximum allowed length for an index name.
#column_name_length	Returns the maximum length of a column name.
#columns_per_multicolumn_index	Returns the maximum number of columns in a multicolumn index.
#columns_per_table	Returns the maximum number of columns per table.
#in_clause_length	Returns the maximum number of elements in an IN (x,y,z) clause.
#index_name_length	Returns the maximum length of an index name.
#indexes_per_table	Returns the maximum number of indexes per table.
#joins_per_query	Returns maximum number of joins in a single query.
#sql_query_length	Returns the maximum length of an SQL query.
#table_alias_length	Returns the maximum length of a table alias.
#table_name_length	Returns the maximum length of a table name.

Quoting - Included

#quote	Quotes the column value to help prevent SQL injection attacks.
#quote_column_name	Quotes the column name.
#quote_string	Quotes a string, escaping any ' (single quote) and \ (backslash) characters.
#quote_table_name	Quotes the table name.
#quote_table_name_for_assignment	Override to return the quoted table name for assignment.
#quoted_date, #quoted_false, #quoted_true,
#type_cast	Cast a `value` to a type that the database understands.
#unquoted_false, #unquoted_true

DatabaseStatements - Included

#add_transaction_record	Register a record with the current transaction so that its after_commit and after_rollback callbacks can be called.
#begin_db_transaction	Begins the transaction (and turns off auto-committing).
#begin_isolated_db_transaction	Begins the transaction with the isolation level set.
#commit_db_transaction	Commits the transaction (and turns on auto-committing).
#default_sequence_name,
#delete	Executes the delete statement and returns the number of rows affected.
#empty_insert_statement_value,
#exec_delete	Executes delete `sql` statement in the context of this connection using `binds` as the bind substitutes.
#exec_insert	Executes insert `sql` statement in the context of this connection using `binds` as the bind substitutes.
#exec_query	Executes `sql` statement in the context of this connection using `binds` as the bind substitutes.
#exec_update	Executes update `sql` statement in the context of this connection using `binds` as the bind substitutes.
#execute	Executes the SQL statement in the context of this connection.
#initialize,
#insert	Returns the last auto-generated ID from the affected table.
#insert_fixture	Inserts the given fixture into the table.
#reset_sequence!	Set the sequence to the max value of the table's column.
#rollback_db_transaction	Rolls back the transaction (and turns on auto-committing).
#rollback_to_savepoint,
#sanitize_limit	Sanitizes the given LIMIT parameter in order to prevent SQL injection.
#select_all	Returns an ::ActiveRecord::Result instance.
#select_one	Returns a record hash with the column names as keys and column values as values.
#select_rows	Returns an array of arrays containing the field values.
#select_value	Returns a single value from a record.
#select_values	Returns an array of the values of the first column in a select:
#to_sql	Converts an arel AST to SQL.
#transaction	Runs the given block in a database transaction, and returns the result of the block.
#transaction_isolation_levels, #transaction_state,
#truncate	Executes the truncate statement.
#update	Executes the update statement and returns the number of rows affected.

SchemaStatements - Included

#add_belongs_to	Alias for SchemaStatements#add_reference.
#add_column	Adds a new column to the named table.
#add_foreign_key	Adds a new foreign key.
#add_index	Adds a new index to the table.
#add_reference	Adds a reference.
#add_timestamps	Adds timestamps (`created_at` and `updated_at`) columns to `table_name`.
#assume_migrated_upto_version,
#change_column	Changes the column's definition according to the new options.
#change_column_default	Sets a new default value for a column:
#change_column_null	Sets or removes a `NOT NULL` constraint on a column.
#change_table	A block for changing columns in `table`.
#column_exists?	Checks to see if a column exists in a given table.
#columns	Returns an array of Column objects for the table specified by `table_name`.
#create_join_table	Creates a new join table with the name created using the lexical order of the first two arguments.
#create_table	Creates a new table with the name `table_name`.
#data_source_exists?	Checks to see if the data source `name` exists on the database.
#data_sources	Returns the relation names useable to back Active Record models.
#drop_join_table	Drops the join table specified by the given arguments.
#drop_table	Drops a table from the database.
#foreign_keys	Returns an array of foreign keys for the given table.
#index_exists?	Checks to see if an index exists on a table for a given index definition.
#index_name_exists?	Verifies the existence of an index with a given name.
#initialize_schema_migrations_table	Should not be called normally, but this operation is non-destructive.
#native_database_types	Returns a hash of mappings from the abstract data types to the native database types.
#remove_belongs_to	Alias for SchemaStatements#remove_reference.
#remove_column	Removes the column from the table definition.
#remove_columns	Removes the given columns from the table definition.
#remove_foreign_key	Removes the given foreign key from the table.
#remove_index	Removes the given index from the table.
#remove_reference	Removes the reference(s).
#remove_timestamps	Removes the timestamp columns (`created_at` and `updated_at`) from the table definition.
#rename_column	Renames a column.
#rename_index	Renames an index.
#rename_table	Renames a table.
#table_alias_for	Truncates a table alias according to the limits of the current adapter.
#table_exists?	Checks to see if the table `table_name` exists on the database.

Constructor Details

.new(connection, logger, connection_options, config) ⇒ `SQLite3Adapter`

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 112


def initialize(connection, logger, connection_options, config)
  super(connection, logger)

  @active     = nil
  @statements = StatementPool.new(@connection,
                                  self.class.type_cast_config_to_integer(config.fetch(:statement_limit) { 1000 }))
  @config = config

  @visitor = Arel::Visitors::SQLite.new self

  if self.class.type_cast_config_to_boolean(config.fetch(:prepared_statements) { true })
    @prepared_statements = true
  else
    @prepared_statements = false
  end
end

Instance Attribute Details

#active? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 164


def active?
  @active != false
end

#requires_reloading? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 156


def requires_reloading?
  true
end

#supports_ddl_transactions? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 129


def supports_ddl_transactions?
  true
end

#supports_explain? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 201


def supports_explain?
  true
end

#supports_index_sort_order? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 181


def supports_index_sort_order?
  true
end

#supports_partial_index? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 137


def supports_partial_index?
  sqlite_version >= '3.8.0'
end

#supports_savepoints? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 133


def supports_savepoints?
  true
end

#supports_statement_cache? ⇒ `Boolean` (readonly)

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

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 143


def supports_statement_cache?
  true
end

#supports_views? ⇒ `Boolean` (readonly)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 160


def supports_views?
  true
end

Instance Method Details

#allowed_index_name_length

Returns 62. SQLite supports index names up to 64 characters. The rest is used by rails internally to perform temporary rename operations

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 188


def allowed_index_name_length
  index_name_length - 2
end

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

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 463


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!

Clears the prepared statements cache.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 177


def clear_cache!
  @statements.clear
end

#create(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)

Alias for #insert_sql.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 334


alias :create :insert_sql

#data_source_exists?(table_name)

Alias for #table_exists?.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 371


alias data_source_exists? table_exists?

#data_sources(name = nil, table_name = nil)

Alias for #tables.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 366


alias data_sources tables

#disconnect!

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

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 170


def disconnect!
  super
  @active = false
  @connection.close rescue nil
end

#encoding

Returns the current database encoding format as a string, eg: 'UTF-8'

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 197


def encoding
  @connection.encoding.to_s
end

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

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 306


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

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

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 276


def exec_query(sql, name = nil, binds = [])
  type_casted_binds = binds.map { |col, val|
    [col, type_cast(val, col)]
  }

  log(sql, name, type_casted_binds) do
    # Don't cache statements if they are not prepared
    if without_prepared_statement?(binds)
      stmt    = @connection.prepare(sql)
      begin
        cols    = stmt.columns
        records = stmt.to_a
      ensure
        stmt.close
      end
      stmt = records
    else
      cache = @statements[sql] ||= {
        :stmt => @connection.prepare(sql)
      }
      stmt = cache[:stmt]
      cols = cache[:cols] ||= stmt.columns
      stmt.reset!
      stmt.bind_params type_casted_binds.map { |_, val| val }
    end

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

#exec_update(sql, name = 'SQL', binds = [])

Alias for #exec_delete.

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 310


alias :exec_update :exec_delete

#explain(arel, binds = [])

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 257


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

#last_inserted_id(result)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 312


def last_inserted_id(result)
  @connection.last_insert_row_id
end

#quote_table_name_for_assignment(table, attr)

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 235


def quote_table_name_for_assignment(table, attr)
  quote_column_name(attr)
end

#rename_table(table_name, new_name)

Renames a table.

Example:

rename_table('octopuses', 'octopi')

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 430


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

#select_rows(sql, name = nil, binds = [])

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 336


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

#table_exists?(table_name) ⇒ `Boolean` Also known as: #data_source_exists?

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 368


def table_exists?(table_name)
  table_name && tables(nil, table_name).any?
end

#valid_alter_table_type?(type) ⇒ `Boolean`

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

[ GitHub ]

# File 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb', line 437


def valid_alter_table_type?(type)
  type.to_sym != :primary_key
end

Class: ActiveRecord::ConnectionAdapters::SQLite3Adapter

Overview

Constant Summary

::ActiveSupport::Callbacks - Included

AbstractAdapter - Inherited

Class Method Summary

AbstractAdapter - Inherited

::ActiveSupport::DescendantsTracker - Inherited

Instance Attribute Summary

AbstractAdapter - Inherited

DatabaseStatements - Included

Instance Method Summary

AbstractAdapter - Inherited

ColumnDumper - Included

::ActiveSupport::Callbacks - Included

::ActiveRecord::QueryCache - Included

DatabaseLimits - Included

Quoting - Included

DatabaseStatements - Included

SchemaStatements - Included

Constructor Details

.new(connection, logger, connection_options, config) ⇒ SQLite3Adapter

Instance Attribute Details

#active? ⇒ Boolean (readonly)

#requires_reloading? ⇒ Boolean (readonly)

#supports_ddl_transactions? ⇒ Boolean (readonly)

#supports_explain? ⇒ Boolean (readonly)

#supports_index_sort_order? ⇒ Boolean (readonly)

#supports_partial_index? ⇒ Boolean (readonly)

#supports_savepoints? ⇒ Boolean (readonly)

#supports_statement_cache? ⇒ Boolean (readonly)

#supports_views? ⇒ Boolean (readonly)

Instance Method Details

#allowed_index_name_length

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

#clear_cache!

#create(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)

#data_source_exists?(table_name)

#data_sources(name = nil, table_name = nil)

#disconnect!

#encoding

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

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

#exec_update(sql, name = 'SQL', binds = [])

#explain(arel, binds = [])

#last_inserted_id(result)

#quote_table_name_for_assignment(table, attr)

#rename_table(table_name, new_name)

#select_rows(sql, name = nil, binds = [])

#table_exists?(table_name) ⇒ Boolean Also known as: #data_source_exists?

#valid_alter_table_type?(type) ⇒ Boolean

.new(connection, logger, connection_options, config) ⇒ `SQLite3Adapter`

#active? ⇒ `Boolean` (readonly)

#requires_reloading? ⇒ `Boolean` (readonly)

#supports_ddl_transactions? ⇒ `Boolean` (readonly)

#supports_explain? ⇒ `Boolean` (readonly)

#supports_index_sort_order? ⇒ `Boolean` (readonly)

#supports_partial_index? ⇒ `Boolean` (readonly)

#supports_savepoints? ⇒ `Boolean` (readonly)

#supports_statement_cache? ⇒ `Boolean` (readonly)

#supports_views? ⇒ `Boolean` (readonly)

#table_exists?(table_name) ⇒ `Boolean` Also known as: #data_source_exists?

#valid_alter_table_type?(type) ⇒ `Boolean`