hi everyone

i have been created  a custom  head/detail tables and the object, windows,screen,funtion, and it work good.

head table:ZPACKH, detail table:ZPACKD

ZPARKH -> index: ZPKID + FCY

ZPACKD  -> index:ZPKID+VCRLIN

i can creation / update / delete records succful 

then i create the import/export template and export one record :

H;TST22050039;FCY1001;alice;danny;2022-07-07;CUS004741
D;1000;ITM1031;456

i change the exported file and change to 

H;TST22050039;FCY1001;jason;danny;2022-07-07;CUS004741
D;1000;ITM1031;123

import the file is successful, but i found deatil data was duplicated。head table was be update normal

H;TST22050039;FCY1001;jason;danny;2022-07-07;CUS004741
D;1000;ITM1031;456
D;1000;ITM1031;123

could anyone help me how to update deatil data? 

thanks al lot