https://community.appian.com/discussions/f/process/18239/nested-cdt-data-writeNot a question, but an interesting topic I found today that I thought was worth sharing. A problem that took some experimentation to figure out was that Nested CDTs will fail on write if the inner CDT foreign key column has a NOT NULL constraint inen-USTelligent Community 12https://community.appian.com/thread/71765?ContentTypeID=1Fri, 31 Jan 2020 14:55:13 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:2b14383f-750f-4d89-9e8f-14d88193d522keviny<p>No we are experimenting with this schema to do a bulk write. So @OneToMany(cascade=CascadeType.ALL)</p><div style="clear:both;"></div>https://community.appian.com/thread/71762?ContentTypeID=1Fri, 31 Jan 2020 14:09:36 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:9f6d6e46-66d6-4150-88cb-90c6ca21b394Peter Lewis<p>Can you clarify what kind of relationship you used and what your Cascade behavior was? Typically if you have a CASCADE=REFRESH behavior, then your nested CDT must already have a primary key that exists in the database for it to work.</p> <p>For instance, suppose I have Customer M:1 Region with CASCADE-REFRESH. In this example, you can only use existing regions; you cannot insert a region at the same time you insert customer.</p> <p>If I misinterpreted your case, can you provide a bit more information about what you tried?</p><div style="clear:both;"></div>