Add multiple inputs in DB

Hi Everyone

I write a form where i need to fill it and at the end to write the data in the DBs.

now i have a problem when i need to write in the Db.

in this project i use Two CDT. owner and customer.

i have one CDT who need to have the id of the previous CDT inserted in the DB.

for exemple i insert the customer in the db , now i need his id and insert it in the owner (CDT) before to insert it in DB.

AS you can see in the image below : i have "ID_Customer" in owner CDT.

Now i outputed the id of the customer (CDT) after that the DB write the data into it ,to put it in the owner (CDT) to update the item and write it in the DB with the id of customer.

now my problem is that i have multiple rows of owner(CDT) how can i do the same process to update each item 's id customer of  each owner ?

i checked the "multiple"  fields  ... is it to write multiple fields at once ??? how can i solve the problem ??

AT the End i want to have two row for example of owner in my db with the same id of customer  .