kedro.io.SQLQueryDataSet¶
-
class
kedro.io.
SQLQueryDataSet
(sql, credentials, load_args=None)[source]¶ Bases:
kedro.io.core.AbstractDataSet
SQLQueryDataSet
loads data from a provided SQL query. It usespandas.DataFrame
internally, so it supports all allowed pandas options onread_sql_query
.It does not support save method so it is a read only data set. To save data to a SQL server use
SQLTableDataSet
.Example:
from kedro.io import SQLQueryDataSet import pandas as pd data = pd.DataFrame({'col1': [1, 2], 'col2': [4, 5], 'col3': [5, 6]}) sql="SELECT * FROM table_a" credentials = { con: "postgresql://scott:tiger@localhost/test" } data_set = SQLQueryDataSet(sql=sql, credentials=credentials) sql_data = data_set.load()
Methods
SQLQueryDataSet.__init__
(sql, credentials[, …])Creates a new SQLQueryDataSet
.SQLQueryDataSet.from_config
(name, config[, …])Create a data set instance using the configuration provided. SQLQueryDataSet.load
()Loads data by delegation to the provided load method. SQLQueryDataSet.save
(data)Saves data by delegation to the provided save method. -
__init__
(sql, credentials, load_args=None)[source]¶ Creates a new
SQLQueryDataSet
.Parameters: - sql (
str
) – The sql query statement. - credentials (
Dict
[str
,Any
]) – A dictionary with aSQLAlchemy
connection string. Users are supposed to provide the connection string ‘con’ through credentials. It overwrites con parameter inload_args
andsave_args
in case it is provided. - load_args (
Optional
[Dict
[str
,Any
]]) – Provided to underlying pandasread_sql_query
function along with the connection string. To find all supported arguments, see here: https://pandas.pydata.org/pandas-docs/stable/generated/pandas.read_sql_query.html
Raises: DataSetError
– When eithersql
orcon
parameters is emtpy.Return type: None
- sql (
-
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.- name (
-
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.
-
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
-