[Question] How terraform decide the resource match the definition?

Is there an existing issue for this?

[X] I have searched the existing issues

What version of the Terraform provider are you using?

1.2.0

What version of the Terraform CLI are you using?

1.8.2

What type of issue are you facing

bug report

Describe the bug

Hi team, In my case, I have existing resource in my trial account and when I read resource info from BTP the out put as following:

    {
      "mode": "data",
      "type": "btp_subaccounts",
      "name": "all",
      "provider": "provider[\"registry.terraform.io/sap/btp\"]",
      "instances": [
        {
          "schema_version": 0,
          "attributes": {
            "id": "6f5168f7trial-ga",
            "labels_filter": null,
            "values": [
              {
                "beta_enabled": false,
                "created_by": "",
                "created_date": "2024-01-30T05:01:44Z",
                "description": "",
                "id": "f842d609-2991-4eec-8efa-e7b5085df21b",
                "labels": null,
                "last_modified": "2024-01-30T05:02:04Z",
                "name": "trial",
                "parent_features": null,
                "parent_id": "1458b4b5-f4a1-4bf6-b252-a4ae365d3146",
                "region": "us10",
                "state": "OK",
                "subdomain": "6f5168f7trial",
                "usage": "UNSET"
              }
            ]

But when I define a new resource as following code

# create a subaccount in us10 region (GCP)
resource "btp_subaccount" "dev" {
  name      = "trial"
  subdomain = "6f5168f7trial"
  region    = "us10"

}

and run command terraform plan the output as following:

Terraform will perform the following actions:

  # btp_subaccount.dev will be created
  + resource "btp_subaccount" "dev" {
      + beta_enabled    = (known after apply)
      + created_by      = (known after apply)
      + created_date    = (known after apply)
      + description     = (known after apply)
      + id              = (known after apply)
      + last_modified   = (known after apply)
      + name            = "trial"
      + parent_features = (known after apply)
      + parent_id       = (known after apply)
      + region          = "us10"
      + state           = (known after apply)
      + subdomain       = "6f5168f7trial"
      + usage           = (known after apply)
    }

Plan: 1 to add, 0 to change, 0 to destroy.

So, I want to know how we test the match of resource and plan definition? I expect my definition should match the exist resource in my case.

Thanks so much.

Expected Behavior

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Steps To Reproduce

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User's Role Collections

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Additional context

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I am not sure, if I get what you want to achieve:

The data source returns all attribute values that are available for the resource and described here: https://registry.terraform.io/providers/SAP/btp/latest/docs/data-sources/subaccount.
The resource has input parameters needed for the creation of the resource. Some of them are mandatory and some of them are optional. In addition, the resources comprises the read-only attributes (that are computed by the platform and known after the application of a resource configuration as given in the documentation https://registry.terraform.io/providers/SAP/btp/latest/docs/resources/subaccount.

If you want to create two subaccounts with the same configuration you can use the data source to get all the data and then map the data to the mandatory and optional parameters of your resource configuration.

Other sceanrios: You can to some extent compare the data when comparing the states of these resources or the result of the data source when reading the data. However, as some computed values are date fields or GUIDs the comparison will not match 100%. In case you want to bring a resource under the management of Terraform, then you must {import](https://developer.hashicorp.com/terraform/language/import) the resource. The data in the state then matches the resource on BTP

A remark on reporting this as a bug: it would be appreciated if you can place questions into the GitHub Discussions and not report them as a bug.

SAP / terraform-provider-btp