hii LIU FENG
firstly you retreive data from association and then you retreive data from database to get list so in second activity write xpath
you have to give xpath when you fetch data from database that equal to or appropriate with associative data of both entity
for example
[MyFirstModule.Registration_TrainingEvent = $TrainingEvent]
[yourModuleName.associationName = RetireiveByAssociationActivityObject]
i hope you will be understand we have done it in Rapid Developer course
Mendix Academy - 7.10.2 Create a registration list
Hi Liu Feng,
maybe I got you wrong, but : if you want to limit your retrieve to the entries that are commited to the database, use retrieve from database instead retrieve by association