add create_table system test

Author: Linchin

google/cloud/bigquery/schema.py

@@ -443,7 +443,7 @@ def _key(self):
             self.description,
             self.fields,
             policy_tags,
-            self._properties.get("timestampPrecision"),
+            self.timestamp_precision,
         )
 
     def to_standard_sql(self) -> standard_sql.StandardSqlField:

tests/system/test_client.py

@@ -74,6 +74,11 @@
     bigquery.SchemaField("full_name", "STRING", mode="REQUIRED"),
     bigquery.SchemaField("age", "INTEGER", mode="REQUIRED"),
 ]
+SCHEMA_PICOSECOND = [
+    bigquery.SchemaField("full_name", "STRING", mode="REQUIRED"),
+    bigquery.SchemaField("age", "INTEGER", mode="REQUIRED"),
+    bigquery.SchemaField("time_pico", "TIMESTAMP", mode="REQUIRED", timestamp_precision=12),
+]
 CLUSTERING_SCHEMA = [
     bigquery.SchemaField("full_name", "STRING", mode="REQUIRED"),
     bigquery.SchemaField("age", "INTEGER", mode="REQUIRED"),
@@ -631,6 +636,20 @@ def test_create_table_w_time_partitioning_w_clustering_fields(self):
         self.assertEqual(time_partitioning.field, "transaction_time")
         self.assertEqual(table.clustering_fields, ["user_email", "store_code"])
 
+    def test_create_tabl_w_picosecond_timestamp(self):
+        dataset = self.temp_dataset(_make_dataset_id("create_table"))
+        table_id = "test_table"
+        table_arg = Table(dataset.table(table_id), schema=SCHEMA_PICOSECOND)
+        self.assertFalse(_table_exists(table_arg))
+
+        table = helpers.retry_403(Config.CLIENT.create_table)(table_arg)
+        self.to_delete.insert(0, table)
+
+        self.assertTrue(_table_exists(table))
+        self.assertEqual(table.table_id, table_id)
+        # breakpoint()
+        self.assertEqual(table.schema, SCHEMA_PICOSECOND)
+
     def test_delete_dataset_with_string(self):
         dataset_id = _make_dataset_id("delete_table_true_with_string")
         project = Config.CLIENT.project