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Active Record SQLite3 适配器 ↑

SQLite3 适配器可与 sqlite3 驱动程序配合使用。

选项 ↑

  • :database (String): 数据库文件的文件系统路径。

  • :statement_limit (Integer): 每个数据库连接缓存的预编译语句的最大数量。（默认值：1000）

  • :timeout (Integer): 等待锁的超时时间（以毫秒为单位）。（默认值：不等待）

  • :strict (Boolean): 启用或禁用严格模式。启用后，此设置将不允许 SQL 语句中使用双引号字符串字面量。（默认值：参见 strict_strings_by_default）

  • :extensions (Array): （**需要 sqlite3 v2.4.0**）每个条目指定一个要加载到此数据库的 sqlite 扩展。条目可以是文件系统路径，也可以是响应 .to_path 方法以提供扩展的文件系统路径的类名。有关更多信息，请参阅 sqlite3-ruby 文档。

可能还有其他特定于 SQLite3 驱动程序的选项。请阅读 SQLite3::Database.new 的文档。

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包含的模块

常量

ADAPTER_NAME = "SQLite"
 
COLLATE_REGEX = /.*"(\w+)".*collate\s+"(\w+)".*/i
 
DEFAULT_PRAGMAS = { "foreign_keys" => true, "journal_mode" => :wal, "synchronous" => :normal, "mmap_size" => 134217728, # 128 megabytes "journal_size_limit" => 67108864, # 64 megabytes "cache_size" => 2000 }
 
DEFERRABLE_REGEX = /DEFERRABLE INITIALLY (\w+)/
 
EXTENDED_TYPE_MAPS = Concurrent::Map.new
 
FINAL_CLOSE_PARENS_REGEX = /\);*\z/
 
FK_REGEX = /.*FOREIGN KEY\s+\("([^"]+)"\)\s+REFERENCES\s+"(\w+)"\s+\("(\w+)"\)/
 
GENERATED_ALWAYS_AS_REGEX = /.*"(\w+)".+GENERATED ALWAYS AS \((.+)\) (?:STORED|VIRTUAL)/i
 
NATIVE_DATABASE_TYPES = { 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" }, json: { name: "json" }, }
 
PRIMARY_KEY_AUTOINCREMENT_REGEX = /.*"(\w+)".+PRIMARY KEY AUTOINCREMENT/i
 
TYPE_MAP = Type::TypeMap.new.tap { |m| initialize_type_map(m) }
 
UNQUOTED_OPEN_PARENS_REGEX = /\((?![^'"]*['"][^'"]*$)/
 
VIRTUAL_TABLE_REGEX = /USING\s+(\w+)\s*\((.+)\)/i
 

类公共方法

dbconsole(config, options = {})

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 60
def dbconsole(config, options = {})
  args = []

  args << "-#{options[:mode]}" if options[:mode]
  args << "-header" if options[:header]
  args << File.expand_path(config.database, defined?(Rails.root) ? Rails.root : nil)

  find_cmd_and_exec(ActiveRecord.database_cli[:sqlite], *args)
end

new(...)

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 129
def initialize(...)
  super

  @memory_database = false
  case @config[:database].to_s
  when ""
    raise ArgumentError, "No database file specified. Missing argument: database"
  when ":memory:"
    @memory_database = true
  when /\Afile:/
  else
    # Otherwise we have a path relative to Rails.root
    @config[:database] = File.expand_path(@config[:database], Rails.root) if defined?(Rails.root)
    dirname = File.dirname(@config[:database])
    unless File.directory?(dirname)
      begin
        FileUtils.mkdir_p(dirname)
      rescue SystemCallError
        raise ActiveRecord::NoDatabaseError.new(connection_pool: @pool)
      end
    end
  end

  @previous_read_uncommitted = nil
  @config[:strict] = ConnectionAdapters::SQLite3Adapter.strict_strings_by_default unless @config.key?(:strict)

  extensions = @config.fetch(:extensions, []).map do |extension|
    extension.safe_constantize || extension
  end

  @connection_parameters = @config.merge(
    database: @config[:database].to_s,
    results_as_hash: true,
    default_transaction_mode: :immediate,
    extensions: extensions
  )
end

new_client(config)

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 50
def new_client(config)
  ::SQLite3::Database.new(config[:database].to_s, config)
rescue Errno::ENOENT => error
  if error.message.include?("No such file or directory")
    raise ActiveRecord::NoDatabaseError
  else
    raise
  end
end

strict_strings_by_default

配置 SQLite3Adapter 以“严格字符串”模式使用。启用后，此设置将不允许 SQL 语句中使用双引号字符串字面量，这可能会防止某些拼写错误，例如为不存在的列创建索引。默认值为 false。

如果您希望启用此模式，可以将以下行添加到您的 application.rb 文件中

config.active_record.sqlite3_adapter_strict_strings_by_default = true

也可以通过设置 strict: 选项在单个数据库上进行配置。

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 94
class_attribute :strict_strings_by_default, default: false

实例公共方法

active?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 242
def active?
  if connected?
    verified!
    true
  end
end

add_timestamps(table_name, **options)

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 425
def add_timestamps(table_name, **options)
  options[:null] = false if options[:null].nil?

  if !options.key?(:precision)
    options[:precision] = 6
  end

  alter_table(table_name) do |definition|
    definition.column :created_at, :datetime, **options
    definition.column :updated_at, :datetime, **options
  end
end

connected?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 238
def connected?
  !(@raw_connection.nil? || @raw_connection.closed?)
end

create_virtual_table(table_name, module_name, values)

创建虚拟表

示例

create_virtual_table :emails, :fts5, ['sender', 'title', 'body']

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 341
def create_virtual_table(table_name, module_name, values)
  exec_query "CREATE VIRTUAL TABLE IF NOT EXISTS #{table_name} USING #{module_name} (#{values.join(", ")})"
end

database_exists?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 167
def database_exists?
  @config[:database] == ":memory:" || File.exist?(@config[:database].to_s)
end

disconnect!()

如果已连接，则断开与数据库的连接。否则，此方法不执行任何操作。

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 253
def disconnect!
  super

  @raw_connection&.close rescue nil
  @raw_connection = nil
end

drop_virtual_table(table_name, module_name, values, **options)

删除虚拟表

虽然此命令会忽略 module_name 和 values，但最好在迁移的 change 方法中提供它们，以便可以撤销。在这种情况下，module_name、values 和 options 将被 create_virtual_table 使用。

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 350
def drop_virtual_table(table_name, module_name, values, **options)
  drop_table(table_name)
end

encoding()

以字符串形式返回当前数据库编码格式，例如‘UTF-8’

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 265
def encoding
  any_raw_connection.encoding.to_s
end

foreign_keys(table_name)

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 445
def foreign_keys(table_name)
  # SQLite returns 1 row for each column of composite foreign keys.
  fk_info = internal_exec_query("PRAGMA foreign_key_list(#{quote(table_name)})", "SCHEMA")
  # Deferred or immediate foreign keys can only be seen in the CREATE TABLE sql
  fk_defs = table_structure_sql(table_name)
              .select do |column_string|
                column_string.start_with?("CONSTRAINT") &&
                column_string.include?("FOREIGN KEY")
              end
              .to_h do |fk_string|
                _, from, table, to = fk_string.match(FK_REGEX).to_a
                _, mode = fk_string.match(DEFERRABLE_REGEX).to_a
                deferred = mode&.downcase&.to_sym || false
                [[table, from, to], deferred]
              end

  grouped_fk = fk_info.group_by { |row| row["id"] }.values.each { |group| group.sort_by! { |row| row["seq"] } }
  grouped_fk.map do |group|
    row = group.first
    options = {
      on_delete: extract_foreign_key_action(row["on_delete"]),
      on_update: extract_foreign_key_action(row["on_update"]),
      deferrable: fk_defs[[row["table"], row["from"], row["to"]]]
    }

    if group.one?
      options[:column] = row["from"]
      options[:primary_key] = row["to"]
    else
      options[:column] = group.map { |row| row["from"] }
      options[:primary_key] = group.map { |row| row["to"] }
    end
    ForeignKeyDefinition.new(table_name, row["table"], options)
  end
end

rename_table(table_name, new_name, **options)

重命名表。

示例

rename_table('octopuses', 'octopi')

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 358
def rename_table(table_name, new_name, **options)
  validate_table_length!(new_name) unless options[:_uses_legacy_table_name]
  schema_cache.clear_data_source_cache!(table_name.to_s)
  schema_cache.clear_data_source_cache!(new_name.to_s)
  exec_query "ALTER TABLE #{quote_table_name(table_name)} RENAME TO #{quote_table_name(new_name)}"
  rename_table_indexes(table_name, new_name, **options)
end

requires_reloading?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 191
def requires_reloading?
  true
end

supports_check_constraints?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 199
def supports_check_constraints?
  true
end

supports_common_table_expressions?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 215
def supports_common_table_expressions?
  true
end

supports_concurrent_connections?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 230
def supports_concurrent_connections?
  !@memory_database
end

supports_datetime_with_precision?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 207
def supports_datetime_with_precision?
  true
end

supports_ddl_transactions?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 171
def supports_ddl_transactions?
  true
end

supports_deferrable_constraints?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 277
def supports_deferrable_constraints?
  true
end

supports_explain?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 269
def supports_explain?
  true
end

supports_expression_index?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 187
def supports_expression_index?
  true
end

supports_foreign_keys?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 195
def supports_foreign_keys?
  true
end

supports_index_sort_order?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 260
def supports_index_sort_order?
  true
end

supports_insert_conflict_target?()

别名：supports_insert_on_conflict?

supports_insert_on_conflict?()

也别名为：supports_insert_on_duplicate_skip?, supports_insert_on_duplicate_update?, supports_insert_conflict_target?

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 223
def supports_insert_on_conflict?
  database_version >= "3.24.0"
end

supports_insert_on_duplicate_skip?()

别名：supports_insert_on_conflict?

supports_insert_on_duplicate_update?()

别名：supports_insert_on_conflict?

supports_insert_returning?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 219
def supports_insert_returning?
  database_version >= "3.35.0"
end

supports_json?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 211
def supports_json?
  true
end

supports_lazy_transactions?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 273
def supports_lazy_transactions?
  true
end

supports_partial_index?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 183
def supports_partial_index?
  true
end

supports_savepoints?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 175
def supports_savepoints?
  true
end

supports_transaction_isolation?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 179
def supports_transaction_isolation?
  true
end

supports_views?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 203
def supports_views?
  true
end

supports_virtual_columns?()

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 234
def supports_virtual_columns?
  database_version >= "3.31.0"
end

virtual_tables()

返回已定义的虚拟表列表

Source: show | on GitHub

# File activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb, line 325
      def virtual_tables
        query = <<~SQL
          SELECT name, sql FROM sqlite_master WHERE sql LIKE 'CREATE VIRTUAL %';
        SQL

        exec_query(query, "SCHEMA").cast_values.each_with_object({}) do |row, memo|
          table_name, sql = row[0], row[1]
          _, module_name, arguments = sql.match(VIRTUAL_TABLE_REGEX).to_a
          memo[table_name] = [module_name, arguments]
        end.to_a
      end