Exceptiongbd_core.api.GBDException - Undocumentedgbd_core.database.DatabaseException - Raised for database-level errors such as missing features, name collisions, or unsupported SQLite operations.gbd_core.grammar.ParserException - Raised when a GBD query string cannot be parsed or when a referenced feature cannot be resolved in the database.gbd_core.schema.SchemaException - Raised for schema-level errors such as missing columns, invalid feature names, CSV import failures, or attempts to merge non-virtual schemas.gbd_core.api.GBD - No class docstring; 0/3 instance variable, 14/17 methods, 2/2 class methods documentedgbd_core.database.Database - Manages multiple ATTACHed SQLite databases as a single virtual feature namespace.gbd_core.grammar.Parser - Parses GBD query strings and compiles them to SQL WHERE fragments.gbd_core.query.GBDQuery - Translates a GBD query string and parameters into a complete SQLite SELECT statement.gbd_core.schema.FeatureInfo - Metadata descriptor for a single GBD feature.gbd_core.schema.Schema - Represents the structure and SQLite connection of one GBD database (or CSV file).