kedro.io.SQLTableDataSet¶
-
class
kedro.io.
SQLTableDataSet
(table_name, credentials, load_args=None, save_args=None)[source]¶ Bases:
kedro.io.core.AbstractDataSet
SQLTableDataSet
loads data from a SQL table and saves a pandas dataframe to a table. It usespandas.DataFrame
internally, so it supports all allowed pandas options onread_sql_table
andto_sql
methods. However, it modifies the save parameters and stores the data with no index. This is designed to make load and save methods symmetric.Example:
from kedro.io import SQLTableDataSet import pandas as pd data = pd.DataFrame({'col1': [1, 2], 'col2': [4, 5], 'col3': [5, 6]}) table_name="table_a" credentials = { con: "postgresql://scott:tiger@localhost/test" } data_set = SQLTableDataSet(table_name=table_name, credentials=credentials) data_set.save(data) reloaded = data_set.load() assert data.equals(reloaded)
Methods
SQLTableDataSet.__init__
(table_name, credentials)Creates a new SQLTableDataSet
.SQLTableDataSet.exists
()Checks whether a data set’s output already exists by calling the provided _exists() method. SQLTableDataSet.from_config
(name, config[, …])Create a data set instance using the configuration provided. SQLTableDataSet.load
()Loads data by delegation to the provided load method. SQLTableDataSet.save
(data)Saves data by delegation to the provided save method. -
__init__
(table_name, credentials, load_args=None, save_args=None)[source]¶ Creates a new
SQLTableDataSet
.Parameters: - table_name (
str
) – The table name to load or save data to. It overwrites name insave_args
andtable_name
parameters inload_args
. - 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_table
function along with the connection string. To find all supported arguments, see here: https://pandas.pydata.org/pandas-docs/stable/generated/pandas.read_sql_table.html - save_args (
Optional
[Dict
[str
,Any
]]) – Provided to underlying pandasto_sql
function along with the connection string. To find all supported arguments, see here: https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.to_sql.html It hasindex=False
in the default parameters.
Raises: DataSetError
– When eithertable_name
orcon
is empty.Return type: None
- table_name (
-
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.
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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.
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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
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