$ pry
[1] pry(main)> require 'sqlite3'
=> true
[2] pry(main)> conn = SQLite3::Database.new("mydb.db")
=> #<SQLite3::Database:0x8d9cda0
 @authorizer=nil,
 @busy_handler=nil,
 @collations={},
 @encoding=nil,
 @functions={},
 @readonly=false,
 @results_as_hash=nil,
 @tracefunc=nil,
 @type_translation=nil>
[3] pry(main)> conn.execute("create table mytable (name text, age integer, phone text);")
=> []
[4] pry(main)> conn.execute("insert into mytable values('Alice', '30', '1234-5678');")
=> []
[5] pry(main)> conn.execute("select * from mytable") {|row| puts row.join "\t" }
Alice	30	1234-5678
=> #<SQLite3::Statement:0x9335974
 @columns=["name", "age", "phone"],
 @connection=
  #<SQLite3::Database:0x8d9cda0
   @authorizer=nil,
   @busy_handler=nil,
   @collations={},
   @encoding=#<Encoding:UTF-8>,
   @functions={},
   @readonly=false,
   @results_as_hash=nil,
   @tracefunc=nil,
   @type_translation=nil>,
 @remainder="",
 @types=["text", "integer", "text"]>
[6] pry(main)> conn.close
=> #<SQLite3::Database:0xa3f08a4
 @authorizer=nil,
 @busy_handler=nil,
 @collations={},
 @encoding=#<Encoding:UTF-8>,
 @functions={},
 @readonly=false,
 @results_as_hash=nil,
 @tracefunc=nil,
 @type_translation=nil>