example.rb

require 'sequel'

Sequel.sqlite do |sqlite|
  sqlite.create_table(:my_table) do
    Date :date
  end

  sqlite[:my_table].insert({ date: "" })

  sqlite[:my_table].each do |row|
    p row[:date]
  end
end

gistfile1.txt

C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/core.rb:265:in `parse': ArgumentError: invalid date (Sequel::InvalidValue)
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/core.rb:265:in `string_to_date'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/adapters/sqlite.rb:25:in `call'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/adapters/sqlite.rb:341:in `block (2 levels) in fetch_rows'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sqlite3-1.3.13-x64-mingw32/lib/sqlite3/resultset.rb:138:in `each'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/adapters/sqlite.rb:334:in `block in fetch_rows'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sqlite3-1.3.13-x64-mingw32/lib/sqlite3/database.rb:267:in `query'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/adapters/sqlite.rb:200:in `block (2 levels) in _execute'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/database/logging.rb:38:in `log_connection_yield'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/adapters/sqlite.rb:200:in `block in _execute'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/database/connecting.rb:253:in `block in synchronize'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/connection_pool/threaded.rb:92:in `hold'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/database/connecting.rb:253:in `synchronize'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/adapters/sqlite.rb:193:in `_execute'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/adapters/sqlite.rb:139:in `execute'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/dataset/actions.rb:1089:in `execute'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/adapters/sqlite.rb:327:in `fetch_rows'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/dataset/actions.rb:152:in `each'
        from main.rb:10:in `block in <main>'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/database/connecting.rb:60:in `connect'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/core.rb:121:in `connect'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/core.rb:399:in `adapter_method'
        from C:/Ruby24-x64/lib/ruby/gems/2.4.0/gems/sequel-5.25.0/lib/sequel/core.rb:406:in `block (2 levels) in def_adapter_method'
        from main.rb:3:in `<main>'