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"""
Example Airflow DAG to show usage of DdlOperator.
This DAG assumes an Airflow Connection with connection id `teradata_default` already exists locally.
It demonstrates how to use DdlOperator to create, drop, alter, and rename Teradata tables and indexes.
"""
from __future__ import annotations
import datetime
import os
import pytest
from airflow import DAG
try:
from airflow.providers.teradata.operators.tpt import DdlOperator
except ImportError:
pytest.skip("TERADATA provider not available", allow_module_level=True)
# [START ddl_operator_howto_guide]
[docs]
ENV_ID = os.environ.get("SYSTEM_TESTS_ENV_ID")
[docs]
DAG_ID = "example_remote_tpt"
[docs]
CONN_ID = "teradata_default"
[docs]
SSH_CONN_ID = "ssh_default"
# Define file paths and table names for the test
[docs]
SYSTEM_TESTS_DIR = os.path.abspath(os.path.dirname(__file__))
[docs]
params = {
"SOURCE_TABLE": "source_table",
"TARGET_TABLE": "target_table",
}
with DAG(
dag_id=DAG_ID,
start_date=datetime.datetime(2020, 2, 2),
schedule="@once",
catchup=False,
default_args={"teradata_conn_id": CONN_ID, "params": params, "ssh_conn_id": SSH_CONN_ID},
) as dag:
# [START ddl_operator_howto_guide_drop_table]
# Drop tables if they exist
[docs]
drop_table = DdlOperator(
task_id="drop_table",
ddl=[
"DROP TABLE {{ params.SOURCE_TABLE }};",
"DROP TABLE {{ params.SOURCE_TABLE }}_UV;",
"DROP TABLE {{ params.SOURCE_TABLE }}_ET;",
"DROP TABLE {{ params.SOURCE_TABLE }}_WT;",
"DROP TABLE {{ params.SOURCE_TABLE }}_Log;",
"DROP TABLE {{ params.TARGET_TABLE }};",
"DROP TABLE {{ params.TARGET_TABLE }}_UV;",
"DROP TABLE {{ params.TARGET_TABLE }}_ET;",
"DROP TABLE {{ params.TARGET_TABLE }}_WT;",
"DROP TABLE {{ params.TARGET_TABLE }}_Log;",
],
error_list=[3706, 3803, 3807],
)
# [END ddl_operator_howto_guide_drop_table]
# [START ddl_operator_howto_guide_create_table]
create_source_table = DdlOperator(
task_id="create_source_table",
ddl=[
"CREATE TABLE {{ params.SOURCE_TABLE }} ( \
first_name VARCHAR(100), \
last_name VARCHAR(100), \
employee_id VARCHAR(10), \
department VARCHAR(50) \
);"
],
)
create_target_table = DdlOperator(
task_id="create_target_table",
ddl=[
"CREATE TABLE {{ params.TARGET_TABLE }} ( \
first_name VARCHAR(100), \
last_name VARCHAR(100), \
employee_id VARCHAR(10), \
department VARCHAR(50) \
);"
],
)
# [END ddl_operator_howto_guide_create_table]
# [START ddl_operator_howto_guide_create_index]
create_index_on_source = DdlOperator(
task_id="create_index_on_source",
ddl=["CREATE INDEX idx_employee_id (employee_id) ON {{ params.SOURCE_TABLE }};"],
)
# [END ddl_operator_howto_guide_create_index]
# [START ddl_operator_howto_guide_rename_table]
rename_target_table = DdlOperator(
task_id="rename_target_table",
ddl=[
"RENAME TABLE {{ params.TARGET_TABLE }} TO {{ params.TARGET_TABLE }}_renamed;",
"DROP TABLE {{ params.TARGET_TABLE }}_renamed",
],
)
# [END ddl_operator_howto_guide_rename_table]
# [START ddl_operator_howto_guide_drop_index]
drop_index_on_source = DdlOperator(
task_id="drop_index_on_source",
ddl=["DROP INDEX idx_employee_id ON {{ params.SOURCE_TABLE }};"],
error_list=[3706, 3803, 3807],
)
# [END ddl_operator_howto_guide_drop_index]
# [START ddl_operator_howto_guide_alter_table]
alter_source_table = DdlOperator(
task_id="alter_source_table",
ddl=["ALTER TABLE {{ params.SOURCE_TABLE }} ADD hire_date DATE;"],
)
# [END ddl_operator_howto_guide_alter_table]
# Define the task dependencies
(
drop_table
>> create_source_table
>> create_target_table
>> create_index_on_source
>> rename_target_table
>> drop_index_on_source
>> alter_source_table
)
from tests_common.test_utils.watcher import watcher
# This test needs watcher in order to properly mark success/failure
# when "tearDown" task with trigger rule is part of the DAG
list(dag.tasks) >> watcher()
from tests_common.test_utils.system_tests import get_test_run # noqa: E402
# Needed to run the example DAG with pytest (see: tests/system/README.md#run_via_pytest)
[docs]
test_run = get_test_run(dag)
# [END ddl_operator_howto_guide]