Set the value for one or more fields of an id. Fields are double precision floating points.
Return value is the integer count of how many fields actually changed their values.
Set a field named
16 and a field named
wheels to 8 for
FSET will return an error if the field is being set on a non-existent id. However, the option
XX can alter this behavior. Specifically, if called with
FSET will return
0 when called on a non-existend id.
Note that the non-existent key will still cause an error!