Schema¶

pydantic model felis.datamodel.Schema¶

Database schema model.

This represents a database schema, which contains one or more tables.

Parameters:

data (Any)

Fields:

resources (dict[str, Resource])
tables (Sequence[Table])
version (SchemaVersion | str | None)

Validators:

_dereference_resource_columns » all fields
_load_resources » all fields
check_constraints » all fields
check_indexes » all fields
check_primary_key » all fields
check_tap_table_indexes » all fields
check_unique_constraint_names » all fields
check_unique_index_names » all fields
check_unique_table_names » tables
create_id_map » all fields
generate_ids » all fields
log_deprecated_id_lookups » all fields

field resources: dict[str, Resource] [Optional]¶

External resources referenced by this schema.

Validated by:

_dereference_resource_columns
_load_resources
check_constraints
check_description
check_indexes
check_primary_key
check_tap_table_indexes
check_unique_constraint_names
check_unique_index_names
create_id_map
generate_ids
log_deprecated_id_lookups

field tables: Sequence[Table] [Required]¶

The tables in the schema.

Validated by:

_dereference_resource_columns
_load_resources
check_constraints
check_description
check_indexes
check_primary_key
check_tap_table_indexes
check_unique_constraint_names
check_unique_index_names
check_unique_table_names
create_id_map
generate_ids
log_deprecated_id_lookups

field version: SchemaVersion | str | None = None¶

The version of the schema.

Validated by:

_dereference_resource_columns
_load_resources
check_constraints
check_description
check_indexes
check_primary_key
check_tap_table_indexes
check_unique_constraint_names
check_unique_index_names
create_id_map
generate_ids
log_deprecated_id_lookups

validator check_constraints » all fields¶

Check constraint objects for validity. This needs to be deferred until after the schema is fully loaded and the ID map is created.

Raises:: pydantic.ValidationError – Raised if any constraints are invalid.
Returns:: The schema being validated.
Return type:: Schema
Parameters:: self (Schema)

validator check_indexes » all fields¶

Check that index column references resolve within their table.

Index columns are resolved by name first, falling back to ID for backward compatibility.

Returns:: The schema being validated.
Return type:: Schema
Raises:: pydantic.ValidationError – Raised if any index references a column that is not found in its table.
Parameters:: self (Schema)

validator check_primary_key » all fields¶

Check that primary key column references resolve within their table.

This validator runs after resource columns have been merged into tables, so all columns are available. Primary key columns are resolved by name first, falling back to ID for backward compatibility.

Returns:: The schema being validated.
Return type:: Schema
Raises:: pydantic.ValidationError – Raised if any primary key column reference is not found in its table.
Parameters:: self (Schema)

validator check_tap_table_indexes » all fields¶

Check that the TAP table indexes are unique.

Parameters:: info (ValidationInfo) – The validation context used to determine if the check is enabled.
Returns:: The schema being validated.
Return type:: Schema

validator check_unique_constraint_names » all fields¶

Check for duplicate constraint names in the schema.

Returns:: The schema being validated.
Return type:: Schema
Raises:: ValueError – Raised if duplicate constraint names are found in the schema.
Parameters:: self (Schema)

validator check_unique_index_names » all fields¶

Check for duplicate index names in the schema.

Returns:: The schema being validated.
Return type:: Schema
Raises:: ValueError – Raised if duplicate index names are found in the schema.
Parameters:: self (Schema)

validator check_unique_table_names » tables¶

Check that table names are unique.

Parameters:: tables (list[Table]) – The tables to check.
Returns:: The tables if they are unique.
Return type:: list [ Table ]
Raises:: ValueError – Raised if table names are not unique.

validator create_id_map » all fields¶

Create a map of IDs to objects.

Returns:: The schema with the ID map created.
Return type:: Schema
Raises:: ValueError – Raised if duplicate identifiers are found in the schema.
Parameters:: self (Schema)

dump_json(stream=<_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'>, strip_ids=False, sort_columns=False)¶

Pretty print the schema as JSON.

Parameters:

stream (IO[str], default: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'>) – The stream to write the JSON data to.
strip_ids (bool, default: False) – Whether to strip the IDs from the dumped data. Defaults to False.
sort_columns (bool, default: False) – Whether to sort columns alphabetically by name. Defaults to False.

Return type:

None

dump_yaml(stream=<_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'>, strip_ids=False, sort_columns=False)¶

Pretty print the schema as YAML.

Parameters:

stream (IO[str], default: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='utf-8'>) – The stream to write the YAML data to.
strip_ids (bool, default: False) – Whether to strip the IDs from the dumped data. Defaults to False.
sort_columns (bool, default: False) – Whether to sort columns alphabetically by name. Defaults to False.

Return type:

None

find_object_by_id(id, obj_type)¶

Find an object with the given type by its ID.

Parameters:

id (str) – The ID of the object to find.
obj_type (type[TypeVar(T, bound= BaseObject)]) – The type of the object to find.

Returns:

The object with the given ID and type.

Return type:

BaseObject

Raises:

KeyError – If the object with the given ID is not found in the schema.
TypeError – If the object that is found does not have the right type.

Notes

The actual return type is the user-specified argument T, which is expected to be a subclass of BaseObject.

classmethod from_stream(source, context={})¶

Load a Schema from a file stream which should contain YAML data.

Parameters:

source (IO[str]) – The file stream to read from.
context (dict[str, Any], default: {}) – Pydantic context to be used in validation.

Returns:

The Felis schema loaded from the stream.

Return type:

Schema

Raises:

yaml.YAMLError – Raised if there is an error loading the YAML file.
pydantic.ValidationError – Raised if the schema fails validation.

classmethod from_uri(resource_path, context={})¶

Load a Schema from a string representing a ResourcePath.

Parameters:

resource_path (str | ParseResult | ResourcePath | Path) – The ResourcePath pointing to a YAML file.
context (dict[str, Any], default: {}) – Pydantic context to be used in validation.

Returns:

The ID of the object.

Return type:

str

Raises:

yaml.YAMLError – Raised if there is an error loading the YAML data.
ValueError – Raised if there is an error reading the resource.
pydantic.ValidationError – Raised if the schema fails validation.

validator generate_ids » all fields¶

Generate IDs for objects that do not have them.

Parameters:

values (dict[str, Any]) – The values of the schema.
info (ValidationInfo) – Validation context used to determine if ID generation is enabled.

Returns:

The values of the schema with generated IDs.

Return type:

dict [ str, Any ]

get_table_by_column(column)¶

Find the table that contains a column.

Parameters:: column (Column) – The column to find.
Returns:: The table that contains the column.
Return type:: Table
Raises:: ValueError – If the column is not found in any table.

validator log_deprecated_id_lookups » all fields¶

Log deprecated ID-based lookups encountered while validating tables.

Returns:: The schema being validated.
Return type:: Schema
Parameters:: self (Schema)