Source code for airflow.providers.snowflake.example_dags.example_snowflake

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"""
Example use of Snowflake related operators.
"""
from datetime import datetime

from airflow import DAG
from airflow.providers.snowflake.operators.snowflake import SnowflakeOperator
from airflow.providers.snowflake.transfers.s3_to_snowflake import S3ToSnowflakeOperator
from airflow.providers.snowflake.transfers.snowflake_to_slack import SnowflakeToSlackOperator

SNOWFLAKE_CONN_ID = 'my_snowflake_conn'
SLACK_CONN_ID = 'my_slack_conn'
# TODO: should be able to rely on connection's schema, but currently param required by S3ToSnowflakeTransfer
SNOWFLAKE_SCHEMA = 'schema_name'
SNOWFLAKE_STAGE = 'stage_name'
SNOWFLAKE_WAREHOUSE = 'warehouse_name'
SNOWFLAKE_DATABASE = 'database_name'
SNOWFLAKE_ROLE = 'role_name'
SNOWFLAKE_SAMPLE_TABLE = 'sample_table'
S3_FILE_PATH = '</path/to/file/sample_file.csv'

# SQL commands
CREATE_TABLE_SQL_STRING = (
    f"CREATE OR REPLACE TRANSIENT TABLE {SNOWFLAKE_SAMPLE_TABLE} (name VARCHAR(250), id INT);"
)
SQL_INSERT_STATEMENT = f"INSERT INTO {SNOWFLAKE_SAMPLE_TABLE} VALUES ('name', %(id)s)"
SQL_LIST = [SQL_INSERT_STATEMENT % {"id": n} for n in range(0, 10)]
SQL_MULTIPLE_STMTS = "; ".join(SQL_LIST)
SNOWFLAKE_SLACK_SQL = f"SELECT name, id FROM {SNOWFLAKE_SAMPLE_TABLE} LIMIT 10;"
SNOWFLAKE_SLACK_MESSAGE = (
    "Results in an ASCII table:\n```{{ results_df | tabulate(tablefmt='pretty', headers='keys') }}```"
)


dag = DAG(
    'example_snowflake',
    start_date=datetime(2021, 1, 1),
    default_args={'snowflake_conn_id': SNOWFLAKE_CONN_ID},
    tags=['example'],
    catchup=False,
)

# [START howto_operator_snowflake]

snowflake_op_sql_str = SnowflakeOperator(
    task_id='snowflake_op_sql_str',
    dag=dag,
    sql=CREATE_TABLE_SQL_STRING,
    warehouse=SNOWFLAKE_WAREHOUSE,
    database=SNOWFLAKE_DATABASE,
    schema=SNOWFLAKE_SCHEMA,
    role=SNOWFLAKE_ROLE,
)

snowflake_op_with_params = SnowflakeOperator(
    task_id='snowflake_op_with_params',
    dag=dag,
    sql=SQL_INSERT_STATEMENT,
    parameters={"id": 56},
    warehouse=SNOWFLAKE_WAREHOUSE,
    database=SNOWFLAKE_DATABASE,
    schema=SNOWFLAKE_SCHEMA,
    role=SNOWFLAKE_ROLE,
)

snowflake_op_sql_list = SnowflakeOperator(task_id='snowflake_op_sql_list', dag=dag, sql=SQL_LIST)

snowflake_op_sql_multiple_stmts = SnowflakeOperator(
    task_id='snowflake_op_sql_multiple_stmts',
    dag=dag,
    sql=SQL_MULTIPLE_STMTS,
)

snowflake_op_template_file = SnowflakeOperator(
    task_id='snowflake_op_template_file',
    dag=dag,
    sql='/path/to/sql/<filename>.sql',
)

# [END howto_operator_snowflake]

# [START howto_operator_s3_to_snowflake]

copy_into_table = S3ToSnowflakeOperator(
    task_id='copy_into_table',
    s3_keys=[S3_FILE_PATH],
    table=SNOWFLAKE_SAMPLE_TABLE,
    schema=SNOWFLAKE_SCHEMA,
    stage=SNOWFLAKE_STAGE,
    file_format="(type = 'CSV',field_delimiter = ';')",
    dag=dag,
)

# [END howto_operator_s3_to_snowflake]

# [START howto_operator_snowflake_to_slack]

slack_report = SnowflakeToSlackOperator(
    task_id="slack_report",
    sql=SNOWFLAKE_SLACK_SQL,
    slack_message=SNOWFLAKE_SLACK_MESSAGE,
    slack_conn_id=SLACK_CONN_ID,
    dag=dag,
)

# [END howto_operator_snowflake_to_slack]

(
    snowflake_op_sql_str
    >> [
        snowflake_op_with_params,
        snowflake_op_sql_list,
        snowflake_op_template_file,
        copy_into_table,
        snowflake_op_sql_multiple_stmts,
    ]
    >> slack_report
)