Azure postgresql flexible server restore with terraform

I have deployed an azure postgresql flexible server using terraform. The terraform code is in a submodule and I include it in the main.tf like this:

module "postgresql" {
  source                      = "./modules/postgreSQL"
  pg_name                     = "${var.pg_name}"
  private_dns_zone            = "${var.pg_private_dns_zone}"
  location                    = data.azurerm_resource_group.resource_group.location
  resource_group_name         = data.azurerm_resource_group.resource_group.name
  ...
  ...
}

The module creates the flexible servers azurerm_postgresql_flexible_server and a couple of databases azurerm_postgresql_flexible_server_database

I tried to create a new flexible server using the point_in_time_restore_time_in_utc feature and importing twice my module with different parameters and the PITR time

module "postgresql" {
  source                      = "./modules/postgreSQL"
  pg_name                     = "${var.pg_name}"
  private_dns_zone            = "${var.pg_private_dns_zone}"
  location                    = data.azurerm_resource_group.resource_group.location
  resource_group_name         = data.azurerm_resource_group.resource_group.name
  ...
  ...
}

# New restored Database  
module "postgresql_new" {
  source                      = "./modules/postgreSQL"
  pg_name                     = "new${var.pg_name}"
  private_dns_zone            = "new${var.pg_private_dns_zone}"
  location                    = data.azurerm_resource_group.resource_group.location
  resource_group_name         = data.azurerm_resource_group.resource_group.name
  ...
  ...
  point_in_time_restore_time_in_utc = "2024-09-22T11:53:37.249000Z"
  source_server_id                  = module.postgresql.pg_id
  create_mode                       = "PointInTimeRestore"
}

Terraform apply fails because it cannot create the databases azurerm_postgresql_flexible_server_database since they are created automatically by Azure with the restore procedure and not by Terraform. Here the errors thrown by terraform

Error: A resource with the ID "/subscriptions/xxxxx/resourceGroups/rgr-zzzz-dev/providers/Microsoft.DBforPostgreSQL/flexibleServers/yyyyy/databases/mydb" 
already exists - to be managed via Terraform this resource needs to be imported into the State.
Please see the resource documentation for "azurerm_postgresql_flexible_server_database" for more information.

How can I solve this issue? or there is another way/workflow that I can use to restore a flexible server in Azure using terraform?

You need to import that resource into Terraform How to import resources into Terraform

1. create an import.tf then get the ID and Module and run it as part of your code.

example:

  import {
  to = azurerm_postgresql_flexible_server_database
  id = "/subscriptions/xxxxx/resourceGroups/rgr-zzzz-dev/providers/Microsoft.DBforPostgreSQL/flexibleServers/yyyyy/databases/mydb"}