I got the same error

Error: cannot create metastore data access: No metastore assigned for the current workspace.

and fixed it by reversing the depends_on order. I am now making databricks_metastore_data_access depend on databricks_metastore_assignment. Here is my code:

resource "databricks_metastore" "this" {

 provider     = databricks.workspace

 name         = "${var.prefix}-metastore"

 storage_root = "s3://${aws_s3_bucket.metastore.id}/metastore"

 delta_sharing_scope = "INTERNAL"

 delta_sharing_recipient_token_lifetime_in_seconds = 120

 force_destroy = true

}

// Assign the metastore to workspaces

resource "databricks_metastore_assignment" "this" {

 provider    = databricks.workspace

 count       = length(var.workspaces)

 metastore_id = databricks_metastore.this.id

 workspace_id = tonumber(replace(var.workspaces[count.index], "/.*//", ""))

 depends_on  = [ databricks_metastore.this ]

}

resource "databricks_metastore_data_access" "metastore_data_access" {

 provider    = databricks.workspace

 metastore_id = databricks_metastore.this.id

 name        = aws_iam_role.metastore_data_access.name

 aws_iam_role { role_arn = aws_iam_role.metastore_data_access.arn }

 is_default  = true

 depends_on  = [ databricks_metastore_assignment.this ]

}