Can I define the next SQL Statement query with entities, do you have some example:

SELECT TASK_CODE, DESCRIPTION FROM COURSE_TASK WHERE COURSE_CODE = 'CLENINO021' AND TASK_CODE NOT IN ( SELECT TASK_CODE FROM COURSE_PREREQ WHERE COURSE_CODE = 'TEST' AND COURSE_REQ = 'CLENINO021')

You certainly can. Take a look at FieldCompareSetPredicates.

Note that by default the FieldCompareSetPredicate will generate code of the form

WHERE x IN (SELECT y FROM Z)

to get a NOT IN there is a negate paramater that needs to be set to true.

Matt