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, obj=None, *, schema=None, database=None, temp=False, overwrite=False)

Create a table.

Parameters:

Name	Type	Description	Default
name	str	Name of the new table.	required
obj	pd.DataFrame | ir.Table | None	An Ibis table expression or pandas table that will be used to extract the schema and the data of the new table. If not provided, schema must be given.	None
schema	sch.Schema | None	The schema for the new table. Only one of schema or obj can be provided.	None
database	str | None	Name of the database where the table will be created, if not the default.	None
temp	bool	Should the table be temporary for the session.	False
overwrite	bool	Clobber existing data	False

Returns:

Type	Description
Table	The table that was created.

drop_table(name, *, database=None, force=False)

Drop a table.

Parameters:

Name	Type	Description	Default
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

raw_sql(query)

Execute a query string.

The returned cursor object must be manually released.

Parameters:

Name	Type	Description	Default
query		DDL or DML statement	required

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

---

Last update: January 4, 2023