DataSourceField Properties

Only one field can be key. IsKey is only used if the data source is for sql objects.

Determines if mapping should be done from parent or child object. It may be null for non parent/child surveys

MapToProperty os inly applicable if the data source is for sql objects and MapTo specifies a reference property. In that case MapToProperty can hold the name of a value property of datatype Text which is present on the data object type which the reference property is for (points to). If MapToProperty is specified then the system will attempt locate a referred data object by looking in the MapToProperty instead of the key property stated on the data object type.

Is either the system name of a property, a fixed field or a reference path (if the data source is OISX) or the name of a sql column (if the data source is SQL)