nested CDTs and Writing Data to Database

RE: nested CDTs and Writing Data to Database

anmolvijayvergiya — Wed, 20 Sep 2023 06:52:22 GMT

RE: nested CDTs and Writing Data to Database

Karthi Premakumari — Tue, 19 Sep 2023 15:12:32 GMT

Appian manages the child key automatically. Your nested phone record could be populated in an editable grid as shown below inside your customer grid. You will notice that nowhere the customer id (key) is being referenced.

a!gridLayout(
label: "Phone Records",
labelPosition: "ABOVE",
emptyGridMessage: "No records found.",
headerCells: {
a!gridLayoutHeaderCell(label: "Phone Number")
},
columnConfigs: {
a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight: 5)
},
rows: a!forEach(
items: fv!item.phoneFK, /* fv!item is your customer variable, depending on how you set it up, it could very well be customer.phoneFK */
expression: a!gridRowLayout(contents: { a!textField() })
),
addRowLink: a!dynamicLink(
label: "Add Phone",
saveInto: a!save(
target: fv!item.phoneFK,
value: append(
fv!item.phoneFK,
'type!{urn:com:appian:types:APP}PHONECDT'()
)
)
)
),

RE: nested CDTs and Writing Data to Database

gangadharr0001 — Mon, 19 Oct 2020 16:38:35 GMT

ankitt

first data store entity just remove save into from input tab and in the output tab stored vales just do data pass back to PV

after that you can use script task in output tab just map first cdt primarky key to second cdt of foreign key .then you can continue with store data to second data store entity

RE: nested CDTs and Writing Data to Database

Ankit Tewari — Mon, 19 Oct 2020 03:38:20 GMT

Hi.I am facing same issue.can you please explain me how you stored the primary key of first cdt and saved it in the second data store entity.

RE: nested CDTs and Writing Data to Database

meredithd0001 — Fri, 01 Mar 2019 17:55:45 GMT

Yes, this post is very old and I have since solved the issue. Which essentially was using flat CDTs and manually maintaining the keys/relationships.

RE: nested CDTs and Writing Data to Database

Stefan Helzle — Fri, 01 Mar 2019 05:10:41 GMT

Did you have a chance to read this: docs.appian.com/.../cdt_design_guidance.html

RE: nested CDTs and Writing Data to Database

lcrostarosa — Thu, 28 Feb 2019 19:35:32 GMT

Lets say you are persisting to the `parent` entity, which is a parent of `nest`with the following data:

```
parent = {
"foo" : "bar",
"nest": {
"hello": "world"
}
}
```

If you just put this data into a write to data store entity, and you have CascadeType.ALL, you should have primary keys for both, as well as a matching foreign key in the foo data

so it will look like

parent:
id: 1
nest_id: 1
foo: bar

nest
id 1
hello: world

RE: nested CDTs and Writing Data to Database

meredithd0001 — Thu, 28 Feb 2019 19:28:10 GMT

I found the same after working on it for a while. I ultimately just used a script task to grab the key from the parent CDT and input it into the child CDT. This worked great. My initial concern was that this methodology was not the correct way. However, it seems to be the cleanest method.

RE: nested CDTs and Writing Data to Database

meredithd0001 — Thu, 28 Feb 2019 19:21:55 GMT

lcrostarosa I may not have explained my initial question well but essentially the key linking the child CDT to my parent CDT was not populating as I expected it to. I went away from this method after researching it more extensively. I found what ManuelHTG found, which was that it was not as easy/clean of a methodology as I initially thought it would be. I did end up just using the process model and script task functionality to grab the parent key and put it in the child CDT. This resulted in a much cleaner process and so far has enabled me to do everything I need. So for anyone looking to do something similar, it seems the best method is to just us the process model to grab the parent keys and put them into the child CDTs.

RE: nested CDTs and Writing Data to Database

ManuelHTG — Thu, 28 Feb 2019 19:16:39 GMT

It should work if you set it up properly. You will need just to save your main CDT and the process should do the rest. I however, never do that. I find messy to handle the nested CDT's and Appian at times does not manage it so well.
What I do is to save the key of the parent CDT on the child CDT's.

RE: nested CDTs and Writing Data to Database

lcrostarosa — Thu, 28 Feb 2019 18:22:20 GMT

Im not sure I understand your question or understand where/if things are breaking.

You can use a write to data store entity in a process or SAIL code as normal

You will have to make sure that you are persisting per your cascade configuration as well