mnemosine.storage.Storage.index_attribute

Kind: method

Signature

Storage.index_attribute(self, attr, as_type='TEXT')

Documentation

Add a generated column and index for a JSON metadata attribute.

See mnemosine.schema.index_json_attribute. Enables fast lookups on dynamic attributes without migrations.

Args:

• attr (str): The metadata attribute to index.
• as_type (str): SQL type: TEXT, INTEGER, REAL or
• BLOB. Defaults to TEXT.

Returns:

• str: The generated column name.

Raises:

• ValueError: If as_type is not a supported SQL type.

Example:

>>> col = db.index_attribute("priority", as_type="INTEGER")
>>> db.conn.execute(f"SELECT count(*) FROM nodes WHERE {col} > 3").fetchone()[0]
0