Plume

Plume is a Ruby library for working with SQLite elegantly. Presently, this means that it provides a pure Ruby implementation of SQLite's lexer/tokenizer as well as a 100% compatible parser. This is useful for introspecting the structure of SQL queries, and for building tools that work with SQL queries.

Installation

Install the gem and add to the application's Gemfile by executing:

bundle add plume

If bundler is not being used to manage dependencies, install the gem by executing:

gem install plume

Usage

Parse a SQL query with the Plume::Parser class:

Note

The parser is still work in progress. Only CREATE TABLE statements are supported at the moment.

sql = <<~SQL
	CREATE TEMP TABLE IF NOT EXISTS `schema0`."tb0" (
		c0 INTEGER PRIMARY KEY DESC ON CONFLICT ABORT AUTOINCREMENT,
		c1 INT NOT NULL ON CONFLICT ROLLBACK,
		c2 TEXT UNIQUE ON CONFLICT IGNORE,
		c3 BLOB CHECK (c3 > 0),
		c4 REAL DEFAULT (1.1 * 2.2),
		c5 ANY COLLATE RTRIM,
		c6 DECIMAL(4, 6) GENERATED ALWAYS AS (1.1 + 2.2) STORED,
		c7 REFERENCES tb1(c1) ON DELETE SET NULL ON UPDATE CASCADE MATCH FULL DEFERRABLE INITIALLY DEFERRED,
		PRIMARY KEY (c0, c1 AUTOINCREMENT) ON CONFLICT ABORT,
		UNIQUE (c0, c1) ON CONFLICT ROLLBACK
		CHECK (c0 > 0)
		FOREIGN KEY (c0) REFERENCES tb1(c1) ON DELETE CASCADE ON UPDATE RESTRICT MATCH FULL DEFERRABLE INITIALLY DEFERRED
	) WITHOUT ROWID;
SQL
ast = Plume::Parser.new(sql).parse.first

# =>
# #<Plume::CreateTableStatement:0x000000011ce3e0a0
#  @columns=
#   [#<Plume::ColumnDefinition:0x000000011ca30828
#     @constraints=
#      [#<Plume::PrimaryKeyColumnConstraint:0x000000011ca34950 @autoincrement=true, @direction=:DESC, @name=nil, @on_conflict=:ABORT>],
#     @name="c0",
#     @type=#<Plume::IntegerType:0x000000011ca3faf8 @constraints=nil, @name="INTEGER">>,
#    #<Plume::ColumnDefinition:0x000000011c857a60
#     @constraints=[#<Plume::NotNullColumnConstraint:0x000000011c8586b8 @name=nil, @on_conflict=:ROLLBACK>],
#     @name="c1",
#     @type=#<Plume::IntegerType:0x000000011c85e978 @constraints=nil, @name="INT">>,
#    #<Plume::ColumnDefinition:0x000000011bf68e68
#     @constraints=[#<Plume::UniqueColumnConstraint:0x000000011bf693e0 @name=nil, @on_conflict=:IGNORE>],
#     @name="c2",
#     @type=#<Plume::TextType:0x000000011c854478 @constraints=nil, @name="TEXT">>,
#    #<Plume::ColumnDefinition:0x000000011ce14bd8
#     @constraints=
#      [#<Plume::CheckColumnConstraint:0x000000011cb73988
#        @expression=
#         #<Plume::BinaryExpression:0x000000011cb761b0
#          @left=#<Plume::ColumnReference:0x000000011cb7dd70 @column_name="c3", @schema_name=nil, @table_name=nil>,
#          @operator=:ABOVE,
#          @right=0>,
#        @name=nil>],
#     @name="c3",
#     @type=#<Plume::BlobType:0x000000011bf67540 @constraints=nil, @name="BLOB">>,
#    #<Plume::ColumnDefinition:0x000000011ce10dd0
#     @constraints=
#      [#<Plume::DefaultColumnConstraint:0x000000011ce11348
#        @name=nil,
#        @value=#<Plume::BinaryExpression:0x000000011ce13bc0 @left=1.1, @operator=:MULTIPLY, @right=2.2>>],
#     @name="c4",
#     @type=#<Plume::RealType:0x000000011ce13ff8 @constraints=nil, @name="REAL">>,
#    #<Plume::ColumnDefinition:0x000000011ccbd258
#     @constraints=[#<Plume::CollateColumnConstraint:0x000000011ccbd7d0 @collation_name=:RTRIM, @name=nil>],
#     @name="c5",
#     @type=#<Plume::AnyType:0x000000011ce10218 @constraints=nil, @name="ANY">>,
#    #<Plume::ColumnDefinition:0x000000011ccb86e0
#     @constraints=
#      [#<Plume::GeneratedAsColumnConstraint:0x000000011ccb8c58
#        @expression=#<Plume::BinaryExpression:0x000000011ccbc588 @left=1.1, @operator=:ADD, @right=2.2>,
#        @name=nil,
#        @type=:STORED>],
#     @name="c6",
#     @type=#<Plume::AnyType:0x000000011ccbcb00 @constraints=[4, 6], @name="DECIMAL">>,
#    #<Plume::ColumnDefinition:0x000000011cabbd88
#     @constraints=
#      [#<Plume::ForeignKeyColumnConstraint:0x000000011cabc5f8
#        @foreign_key_clause=
#         #<Plume::ForeignKeyClause:0x000000011ccb0620
#          @columns=["c1"],
#          @deferred=true,
#          @foreign_table="tb1",
#          @match_name="FULL",
#          @on_delete=:SET_NULL,
#          @on_update=:CASCADE>,
#        @name=nil>],
#     @name="c7",
#     @type=nil>],
#  @constraints=
#   [#<Plume::PrimaryKeyTableConstraint:0x000000011bf0cca8
#     @autoincrement=true,
#     @columns=
#      [#<Plume::IndexedColumn:0x000000011cab67e8
#        @collation=nil,
#        @column=#<Plume::ColumnReference:0x000000011cabb608 @column_name="c0", @schema_name=nil, @table_name=nil>,
#        @direction=nil,
#        @expression=nil>,
#       #<Plume::IndexedColumn:0x000000011be0d258
#        @collation=nil,
#        @column=#<Plume::ColumnReference:0x000000011cab6630 @column_name="c1", @schema_name=nil, @table_name=nil>,
#        @direction=nil,
#        @expression=nil>],
#     @name=nil,
#     @on_conflict=:ABORT>,
#    #<Plume::UniqueTableConstraint:0x000000011beabef8
#     @columns=
#      [#<Plume::IndexedColumn:0x000000011be08208
#        @collation=nil,
#        @column=#<Plume::ColumnReference:0x000000011bf0c190 @column_name="c0", @schema_name=nil, @table_name=nil>,
#        @direction=nil,
#        @expression=nil>,
#       #<Plume::IndexedColumn:0x000000011be08168
#        @collation=nil,
#        @column=#<Plume::ColumnReference:0x000000011bf0bf38 @column_name="c1", @schema_name=nil, @table_name=nil>,
#        @direction=nil,
#        @expression=nil>],
#     @name=nil,
#     @on_conflict=:ROLLBACK>,
#    #<Plume::CheckTableConstraint:0x000000011be8df20
#     @expression=
#      #<Plume::BinaryExpression:0x000000011bea8f28
#       @left=#<Plume::ColumnReference:0x000000011bea9130 @column_name="c0", @schema_name=nil, @table_name=nil>,
#       @operator=:ABOVE,
#       @right=0>,
#     @name=nil>,
#    #<Plume::ForeignKeyTableConstraint:0x000000011be804b0
#     @columns=
#      [#<Plume::IndexedColumn:0x000000011be02da8
#        @collation=nil,
#        @column=#<Plume::ColumnReference:0x000000011be8d818 @column_name="c0", @schema_name=nil, @table_name=nil>,
#        @direction=nil,
#        @expression=nil>],
#     @foreign_key_clause=
#      #<Plume::ForeignKeyClause:0x000000011be02cb8
#       @columns=["c1"],
#       @deferred=true,
#       @foreign_table="tb1",
#       @match_name="FULL",
#       @on_delete=:CASCADE,
#       @on_update=:RESTRICT>,
#     @name=nil>],
#  @if_not_exists=true,
#  @options=[#<Plume::WithoutRowidTableOption:0x0000000100a1a9e0>],
#  @schema_name="schema0",
#  @select_statement=nil,
#  @strict=nil,
#  @table_name="tb0",
#  @temporary=true,
#  @without_row_id=true>

Tokenize a SQL query with the Plume::Lexer class:

lexer = Plume::Lexer.new("SELECT * FROM users WHERE id = 1")
tokens = lexer.tokens.to_a
# =>
# [:SELECT,
#  :SPACE,
#  :STAR,
#  :SPACE,
#  :FROM,
#  :SPACE,
#  :ID,
#  :SPACE,
#  :WHERE,
#  :SPACE,
#  :ID,
#  :SPACE,
#  :EQ,
#  :SPACE,
#  :INTEGER]

SQLite works with a grammar of 167 token types, 136 of which are keywords. The remaining 31 are punctuation, operators, and literals.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/fractaledmind/plume. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Plume project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.