READ ENTITY in SAP RAP unmanaged On Premise version 1909 does not read buffer data

[florenca]

Good Day,

I am having issues with READ ENTITY in SAP RAP unmanaged On Premise version 1909.

I am unable to retrieve any data from the Transactional buffer by using READ ENTITY cdsview.

I would like to know how the Transactional buffer is populated after the user presses 'Go'?

I want to READ the buffer during an Update operation so that I can check

that the record that is currently being updated and is in the buffer hasn't, in the meantime, being changed by another user in the back-end.

I thought that the eTag functionality would take care of this, but it doesn't seem to be working in my case.

The UPDATE method only brings back the changed fields and so I cannot compare the other fields with the current values in the database.

The READ ENTITY cdsview command takes me to the READ method in the Behaviour defintion Handler class.

From here, I don't know how to access the buffer data.

All the examples in the documentation, make use of the FUNCTION '/DMO/FLIGHT_TRAVEL_READ' , but it is not clear how the buffer initially gets populated after the user presses 'Go'.

Any inputs would be created appreciated.

Thank you in advance.

[lloydfernandes]

Hello Antonio,

The unmanaged scenario is used when you have APIs available to handle the processing of your data model. Most APIs are designed in a way that they contain buffers to store input data at runtime.

If you do not have APIs available, you'd need to explicitly define a buffer and populate it in the CREATE, UPDATE and DELETE methods. Similarly, you would need to read from the buffer and populate the RESULT parameter in the READ method.

[florenca]

Good Day Lloyd,

Just to add to my response below: I do populate the RESULT parameter in the READ method, but when I get to the Update Method, the custom buffer table is empty again.

Any suggestions will be apprciated.

Thank you in advance.