AX 2009 services - update operation

[ist]

Hi guys,

I have a problem with AX web service when I'm using update operation.
This is my scenario:

My query is based on two tables - parent (TestServiceHeader ) an child (TestServiceLine). Only parent datasource can be updated. (datasource property Update = Yes).
In order to use update service operation, I have to use read operation first. When I execute read operation AX returns instances for each tables (Ax...class objects) which are parts of the query. When I try to update TestServiceHeader table AX throws an exception. For this reason the instance of TestServiceLine has beeen set to null - red bordered row.
Is there any way to do that (without set to null child datasource)?

As you can see on the screenshot I want to update only header table.



Thanks,
ist