SQLAlchemy Backend Base Classes

BaseAlchemyBackend

Bases: BaseSQLBackend

Backend class for backends that compile to SQLAlchemy expressions.

Attributes

current_database: str property

The name of the current database this client is connected to.

Functions

create_table(name, expr=None, schema=None, database=None, force=False)

Create a table.

Parameters:

Name	Type	Description	Default
name	str	Table name to create	required
expr	pd.DataFrame | ir.Table | None	DataFrame or table expression to use as the data source	None
schema	sch.Schema | None	An ibis schema	None
database	str | None	A database	None
force	bool	Check whether a table exists before creating it	False

drop_table(table_name, database=None, force=False)

Drop a table.

Parameters:

Name	Type	Description	Default
table_name	str	Table to drop	required
database	str | None	Database to drop table from	None
force	bool	Check for existence before dropping	False

insert(table_name, obj, database=None, overwrite=False)

Insert data into a table.

Parameters:

Name	Type	Description	Default
table_name	str	The name of the table to which data needs will be inserted	required
obj	pd.DataFrame | ir.Table | list | dict	The source data or expression to insert	required
database	str | None	Name of the attached database that the table is located in.	None
overwrite	bool	If True then replace existing contents of table	False

Raises:

Type	Description
NotImplementedError	If inserting data from a different database
ValueError	If the type of obj isn't supported

list_databases(like=None)

List databases in the current server.

load_data(table_name, data, database=None, if_exists='fail')

Load data from a dataframe to the backend.

Parameters:

Name	Type	Description	Default
table_name	str	Name of the table in which to load data	required
data	pd.DataFrame	Pandas DataFrame	required
database	str | None	Database in which the table exists	None
if_exists	Literal['fail', 'replace', 'append']	What to do when data in name already exists	'fail'

Raises:

Type	Description
NotImplementedError	Loading data to a table from a different database is not yet implemented

schema(name)

Get an ibis schema from the current database for the table name.

Parameters:

Name	Type	Description	Default
name	str	Table name	required

Returns:

Type	Description
Schema	The ibis schema of name

table(name, database=None, schema=None)

Create a table expression from a table in the database.

Parameters:

Name	Type	Description	Default
name	str	Table name	required
database	str | None	The database the table resides in	None
schema	str | None	The schema inside database where the table resides. schema refers to database organization The schema parameter does not refer to the column names and types of table.	None

Returns:

Type	Description
Table	Table expression

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Last update: January 4, 2023