query using "for json"

query using "for json"

Hello,
I use SDAC 10.0.2 with delphi 7,
When I try follow query that return one row & one field (actually is TMemoField) and get field value as string I get part of actual data (2033 bytes). 
Can anyone knows what is wrong?

select * from customer
for json auto
I post same question in support but I did not get any response 27 days ago.