bigquery: add a function to get the SQL table ID from a Table

stats.py

@@ -462,8 +462,8 @@ def create_staging_tables(
     staging table.
     """
     return {
-        table.full_table_id: bq_client.create_table(
-            bigquery.Table(staging_table_id(table.full_table_id), schema=table.schema),
+        sql_table_id(table): bq_client.create_table(
+            bigquery.Table(staging_table_id(sql_table_id(table)), schema=table.schema),
             exists_ok=True,
         )
         for table in tables.values()
@@ -512,6 +512,15 @@ def staging_table_id(table_id: str) -> str:
     return f"{table_id}_staging"
 
 
+def sql_table_id(table: bigquery.Table) -> str:
+    """Return a fully-qualified ID in standard SQL format.
+
+    Return in the format `project.dataset_id.table_id`, since `Table.full_table_id`
+    returns as `project:dataset_id.table_id`.
+    """
+    return f"{table.project}.{table.dataset_id}.{table.table_id}"
+
+
 def merge_into_bigquery(
     bq_client: bigquery.Client,
     table_id: str,
@@ -560,11 +569,11 @@ def submit_to_bigquery(
 
     # Insert rows into staging table.
     for chunk in chunked(rows, 500):
-        errors = bq_client.insert_rows_json(table.full_table_id, chunk)
+        errors = bq_client.insert_rows_json(sql_table_id(table), chunk)
         if errors:
             logging.error(
                 "Encountered errors while inserting rows to "
-                f"{table.full_table_id}: {errors}."
+                f"{sql_table_id(table)}: {errors}."
             )
             sys.exit(1)