kedro_datasets.spark.SparkJDBCDataset¶
- class kedro_datasets.spark.SparkJDBCDataset(*, url, table, credentials=None, load_args=None, save_args=None, metadata=None)[source]¶
SparkJDBCDataset
loads data from a database table accessible via JDBC URL url and connection properties and saves the content of a PySpark DataFrame to an external database table via JDBC. It usespyspark.sql.DataFrameReader
andpyspark.sql.DataFrameWriter
internally, so it supports all allowed PySpark options onjdbc
.Example usage for the YAML API:
weather: type: spark.SparkJDBCDataset table: weather_table url: jdbc:postgresql://localhost/test credentials: db_credentials load_args: properties: driver: org.postgresql.Driver save_args: properties: driver: org.postgresql.Driver
Example usage for the Python API:
import pandas as pd from kedro_datasets.spark import SparkJDBCDataset from pyspark.sql import SparkSession spark = SparkSession.builder.getOrCreate() data = spark.createDataFrame( ... pd.DataFrame({"col1": [1, 2], "col2": [4, 5], "col3": [5, 6]}) ... ) url = "jdbc:postgresql://localhost/test" table = "table_a" connection_properties = {"driver": "org.postgresql.Driver"} dataset = SparkJDBCDataset( ... url=url, ... table=table, ... credentials={"user": "scott", "password": "tiger"}, ... load_args={"properties": connection_properties}, ... save_args={"properties": connection_properties}, ... ) dataset.save(data) reloaded = dataset.load() assert data.toPandas().equals(reloaded.toPandas())
Attributes
Methods
exists
()Checks whether a data set's output already exists by calling the provided _exists() method.
from_config
(name, config[, load_version, ...])Create a data set instance using the configuration provided.
load
()Loads data by delegation to the provided load method.
release
()Release any cached data.
save
(data)Saves data by delegation to the provided save method.
- __init__(*, url, table, credentials=None, load_args=None, save_args=None, metadata=None)[source]¶
Creates a new
SparkJDBCDataset
.- Parameters:
url (
str
) – A JDBC URL of the formjdbc:subprotocol:subname
.table (
str
) – The name of the table to load or save data to.credentials (
Optional
[dict
[str
,Any
]]) – A dictionary of JDBC database connection arguments. Normally at least propertiesuser
andpassword
with their corresponding values. It updatesproperties
parameter inload_args
andsave_args
in case it is provided.load_args (
Optional
[dict
[str
,Any
]]) – Provided to underlying PySparkjdbc
function along with the JDBC URL and the name of the table. To find all supported arguments, see here: https://spark.apache.org/docs/latest/api/python/reference/pyspark.sql/api/pyspark.sql.DataFrameWriter.jdbc.htmlsave_args (
Optional
[dict
[str
,Any
]]) – Provided to underlying PySparkjdbc
function along with the JDBC URL and the name of the table. To find all supported arguments, see here: https://spark.apache.org/docs/latest/api/python/reference/pyspark.sql/api/pyspark.sql.DataFrameWriter.jdbc.htmlmetadata (
Optional
[dict
[str
,Any
]]) – Any arbitrary metadata. This is ignored by Kedro, but may be consumed by users or external plugins.
- Raises:
DatasetError – When either
url
ortable
is empty or when a property is provided with a None value.
- exists()¶
Checks whether a data set’s output already exists by calling the provided _exists() method.
- Return type:
- Returns:
Flag indicating whether the output already exists.
- Raises:
DatasetError – when underlying exists method raises error.
- classmethod from_config(name, config, load_version=None, save_version=None)¶
Create a data set instance using the configuration provided.
- Parameters:
name (str) – Data set name.
load_version (str | None) – Version string to be used for
load
operation if the data set is versioned. Has no effect on the data set if versioning was not enabled.save_version (str | None) – Version string to be used for
save
operation if the data set is versioned. Has no effect on the data set if versioning was not enabled.
- Return type:
AbstractDataset
- Returns:
An instance of an
AbstractDataset
subclass.- Raises:
DatasetError – When the function fails to create the data set from its config.
- load()¶
Loads data by delegation to the provided load method.
- Return type:
TypeVar
(_DO
)- Returns:
Data returned by the provided load method.
- Raises:
DatasetError – When underlying load method raises error.
- release()¶
Release any cached data.
- Raises:
DatasetError – when underlying release method raises error.
- Return type:
- save(data)¶
Saves data by delegation to the provided save method.
- Parameters:
data (
TypeVar
(_DI
)) – the value to be saved by provided save method.- Raises:
DatasetError – when underlying save method raises error.
FileNotFoundError – when save method got file instead of dir, on Windows.
NotADirectoryError – when save method got file instead of dir, on Unix.
- Return type: