Query class field in VDATA
A class field is a block of sub-fields. You cannot query a class field such as SELECT Respondent FROM VDATA. You can however query sub-fields in a class field because although class fields are not columns in VDATA, sub-fields are treated as columns.
Example
In the following example (based on data from the UNICOM Intelligence Developer Library museum.mdd example), the Respondent field is a class that includes the Serial and Origin sub-fields. The person field is bound from 1 to 6. To query the Serial and Origin field data, the query statement would be:
SELECT Respondent.Serial
, Respondent.Origin
FROM VDATA
The result data is:
|
Respondent.Serial
|
Respondent.Origin
|
|
1
|
(null)
|
|
2
|
(null)
|
|
3
|
(null)
|
See also