### TODO
- escape " in save csv
- is null | is not null
- coalesce, date functions now, add_date; string functions rtrim, ltrim, rpad, lpad; math function round
- add pipe | concatenation
- add support for 1_000_000 numbers

- support for order by, offset, limit (allow column name in order by, validate)
- support for uniqueue indexes (primary key)
- support for btree indexes
- support for joining
- add count min and max functions, eg aggregate functions

- use string_to_double and string_to_long (from Table) everywhere
- add const wherever should be
- use static methods where posible
- use references where pointer cannot be nullptr