hypernets_processor.data_io.database_util module

DatabaseUtil class

class hypernets_processor.data_io.database_util.DatabaseUtil

Bases: object

Class to provide utilities for generating databases

static apply_schema_dict(db, schema_dict)

Initialise database with defined schema

Parameters:

• db (dataset.Dataset) – empty database to initialise

• schema_dict (dict) – dictionary defining database schema

Each entry in the dictionary is the name of a table to be defined, the value of each entry is a dictionary that defines the table, it has the following entries:

• “columns” - defines the table columns

  each entry in the dictionary is the name of a column to be defined, the value of each entry is a dictionary that defines the column, this has entries:

  • “type” - defines the column type, value should be python type

  • “foreign_key” (optional) - defines if column is foreign key to reference table. Value is dictionary structured as: {“reference_table”: “<table_name>”, “reference_column”: “column_name”}. NB: This is not supported for defining sqlite databases. If this is required, please define as SQL command (option b)

  • other entries may be kwargs supported by dataset.table.Table.create_column

• “primary_key” - defines the tables primary key, value is the column name.

• other entries may be kwargs supported by dataset.database.Database.create_table

static create_db(url)

Create database at defined url (sqlite or postgresql)

Parameters:

url (str) – url of database to create

Returns:

New database

Return type:

dataset.Database

static delete_db(url)

static get_db_type(python_type)

Returns sqlalchemy type equivalent to given python type

Parameters:

python_type (type) – python type

Returns:

equivalent sqlalchemy type

Return type:

sqlalchemy.sql.visitors.VisitableType

static update_to_foreign_key(db, table, column, reference_table, reference_column)

Update database to set column as foreign key to reference table and column

Parameters:

• db (dataset.Dataset) – empty database to initialise

• table (str) – name of table with column to set as foreign key

• column (str) – name of column to set as foreign key

• reference_table (str) – name of table with column to set foreign key to

• reference_column (str) – name of column to set foreign key to

hypernets_processor.data_io.database_util.create_template_db(url, schema_dict=None, schema_sql=None)

Create database at defined url and initialise database with defined schema

Parameters:

• url (str) – url of database to create

• schema_dict (dict) – dictionary defining database schema

Each entry in the dictionary is the name of a table to be defined, the value of each entry is a dictionary that defines the table, it has the following entries:

• “columns” - defines the table columns

  each entry in the dictionary is the name of a column to be defined, the value of each entry is a dictionary that defines the column, this has entries:

  • “type” - defines the column type, value should be python type

  • “foreign_key” (optional) - defines if column is foreign key to reference table. Value is dictionary structured as: {“reference_table”: “<table_name>”, “reference_column”: “column_name”}. NB: This is not supported for defining sqlite databases. If this is required, please define as SQL command (option b)

  • other entries may be kwargs supported by dataset.table.Table.create_column

• “primary_key” - defines the tables primary key, value is the column name.

• other entries may be kwargs supported by dataset.database.Database.create_table

Parameters:

schema_sql (str) – sql command to create database schema

Databases may be defined with SQL commands as strings

Returns:

Initialised database

Return type:

dataset.Database