Possible field types:
- string
- number
- integer - whole number
- float, decimal - number with possible fractional part
- boolean - true or false
- date - string representing date in ISO-8601 format (YYYY-MM-DD)
- time - string representing time of day in 24-hour format (HH:MM)
- date and time - string representing time at date in ISO-8601 format (YYYY-MM-DD HH:MM)
- enumeration - string value chosen from finite set, see Standard enumerated columns