9. API: FetchInfo Objects

FetchInfo objects are created internally when a query is executed. They are found in the sequence Cursor.description. There is one FetchInfo object for each column. For compatibility with the Python Database API, this object behaves as a 7-tuple containing the values for the attributes name, type_code, display_size, internal_size, precision, scale, and null_ok in that order. For example, if fetch_info is of type FetchInfo, then fetch_info[2] is the same as fetch_info.display_size.

This object is an extension to the DB API definition.

Added in version 1.4.0.

9.1. FetchInfo Attributes

FetchInfo.annotations: This read-only attribute returns a dictionary containing the annotations associated with the fetched column. If there are no annotations, the value None is returned. Annotations require Oracle Database 23ai. If using python-oracledb Thick mode, Oracle Client 23ai is also required.

Added in version 2.0.0.

FetchInfo.display_size: This read-only attribute returns the display size of the column as mandated by the Python Database API.

FetchInfo.domain_name: This read-only attribute returns the name of the data use case domain associated with the fetched column. If there is no data use case domain, the value None is returned. Data use case domains require Oracle Database 23ai. If using python-oracledb Thick mode, Oracle Client 23ai is also required.

Added in version 2.0.0.

FetchInfo.domain_schema: This read-only attribute returns the schema of the data use case domain associated with the fetched column. If there is no data use case domain, the value None is returned. Data use case domains require Oracle Database 23ai. If using python-oracledb Thick mode, Oracle Client 23ai is also required.

Added in version 2.0.0.

FetchInfo.internal_size: This read-only attribute returns the internal size of the column as mandated by the Python Database API.

FetchInfo.is_json: This read-only attribute returns whether the column is known to contain JSON data. This will be True when the type code is oracledb.DB_TYPE_JSON as well as when an “IS JSON” constraint is enabled on LOB and VARCHAR2 columns.

FetchInfo.is_oson: This read-only attribute returns whether the column is known to contain binary encoded OSON data. This will be True when an “IS JSON FORMAT OSON” check constraint is enabled on BLOB columns.

Added in version 2.1.0.

FetchInfo.name: This read-only attribute returns the name of the column as mandated by the Python Database API.

FetchInfo.null_ok: This read-only attribute returns whether nulls are allowed in the column as mandated by the Python Database API.

FetchInfo.precision: This read-only attribute returns the precision of the column as mandated by the Python Database API.

FetchInfo.scale: This read-only attribute returns the scale of the column as mandated by the Python Database API.

FetchInfo.type: This read-only attribute returns the type of the column. This will be an Oracle Object Type if the column contains Oracle objects; otherwise, it will be one of the database type constants defined at the module level.

FetchInfo.type_code: This read-only attribute returns the type of the column as mandated by the Python Database API. The type will be one of the database type constants defined at the module level.

FetchInfo.vector_dimensions: This read-only attribute returns the number of dimensions required by VECTOR columns. If the column is not a VECTOR column or allows for any number of dimensions, the value returned is None.

Added in version 2.2.0.

FetchInfo.vector_format

This read-only attribute returns the storage format used by VECTOR columns. The value of this attribute can be:

oracledb.VECTOR_FORMAT_BINARY which represents 8-bit unsigned integers
oracledb.VECTOR_FORMAT_INT8 which represents 8-bit signed integers
oracledb.VECTOR_FORMAT_FLOAT32 which represents 32-bit floating-point numbers
oracledb.VECTOR_FORMAT_FLOAT64 which represents 64-bit floating-point numbers

If the column is not a VECTOR column or allows for any type of storage, the value returned is None.

Added in version 2.2.0.

FetchInfo.vector_is_sparse

This read-only attribute returns a boolean that indicates whether the vector is sparse or not.

If the column contains vectors that are SPARSE, the value returned is True. If the column contains vectors that are DENSE, the value returned is False. If the column is not a VECTOR column, the value returned is None.

Added in version 3.0.0.