kedro.extras.datasets.spark.SparkJDBCDataSet¶
-
class
kedro.extras.datasets.spark.
SparkJDBCDataSet
(url, table, credentials=None, load_args=None, save_args=None)[source]¶ Bases:
kedro.io.core.AbstractDataSet
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:
import pandas as pd 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'} data_set = SparkJDBCDataSet( url=url, table=table, credentials={'user': 'scott', 'password': 'tiger'}, load_args={'properties': connection_properties}, save_args={'properties': connection_properties}) data_set.save(data) reloaded = data_set.load() assert data.toPandas().equals(reloaded.toPandas())
Attributes
Methods
Checks whether a data set’s output already exists by calling the provided _exists() method.
SparkJDBCDataSet.from_config
(name, config[, …])Create a data set instance using the configuration provided.
Loads data by delegation to the provided load method.
Release any cached data.
SparkJDBCDataSet.save
(data)Saves data by delegation to the provided save method.
-
DEFAULT_LOAD_ARGS
: Dict[str, Any] = {}¶
-
DEFAULT_SAVE_ARGS
: Dict[str, Any] = {}¶
-
__init__
(url, table, credentials=None, load_args=None, save_args=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/api/pyspark.sql.DataFrameReader.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/api/pyspark.sql.DataFrameWriter.jdbc.html
- 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
bool
- 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.config (
Dict
[str
,Any
]) – Data set config dictionary.load_version (
Optional
[str
]) – Version string to be used forload
operation if the data set is versioned. Has no effect on the data set if versioning was not enabled.save_version (
Optional
[str
]) – Version string to be used forsave
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
Any
- 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
None
-
save
(data)¶ Saves data by delegation to the provided save method.
- Parameters
data (
Any
) – the value to be saved by provided save method.- Raises
DataSetError – when underlying save method raises error.
- Return type
None
-