Descriptors and Desktop Database Drivers
A descriptor is a data structure that holds information about either column data or dynamic parameters. SQLGetDescField can be used to retrieve the supported descriptors listed below. Implementation Parameter Descriptors (IPD) are not automatically populated because SQLDescribeParam is not supported. Descriptor fields that are not available through Jet (such as SQL_DESC_BASE_TABLE_NAME) are also not supported.
For more information about Jet-supported descriptor fields, see the Microsoft Jet Database Engine Programmer's Guide.
For more information about descriptors, see the topics under "Descriptors" in the ODBC Programmer's Reference.
| Descriptor fields | Support level |
|---|---|
| SQL_DESC_ALLOC_TYPE | Supported |
| SQL_DESC_ARRAY_SIZE | Supported only for ARD |
| SQL_DESC_ARRAY_STATUS_PTR | Supported |
| SQL_DESC_BIND_OFFSET_PTR | Supported |
| SQL_DESC_BIND_TYPE | Supported |
| SQL_DESC_COUNT | Supported |
| SQL_DESC_ROWS_PROCESSED_PTR | Supported only for ARD |
| SQL_DESC_AUTO_UNIQUE_VALUE | Supported |
| SQL_DESC_BASE_COLUMN_NAME | Supported (NEW) |
| SQL_DESC_BASE_TABLE_NAME | Supported (NEW) |
| SQL_DESC_CASE_SENSITIVE | Always FALSE |
| SQL_DESC_CATALOG_NAME | Not supported |
| SQL_DESC_CONCISE_TYPE | Supported |
| SQL_DESC_DATA_PTR | Supported |
| SQL_DESC_DATETIME_INTERVAL_CODE | Supported |
| SQL_DESC_DATETIME_INTERVAL_PRECISION | Supported for INTERVAL C types |
| SQL_DESC_DISPLAY_SIZE | Supported |
| SQL_DESC_FIXED_PREC_SCALE | Supported (TRUE for money) |
| SQL_DESC_INDICATOR_PTR | Supported |
| SQL_DESC_LABEL | Supported |
| SQL_DESC_LENGTH | Supported |
| SQL_DESC_LITERAL_PREFIX | Supported |
| SQL_DESC_LITERAL_SUFFIX | Supported |
| SQL_DESC_LOCAL_TYPE_NAME | Not supported (returns EMPTY string) |
| SQL_DESC_NAME | Supported |
| SQL_DESC_NULLABLE | Supported Note Unsupported in versions preceding Jet 4.0 |
| SQL_DESC_NUM_PREC_RADIX | Supported |
| SQL_DESC_OCTET_LENGTH | Supported |
| SQL_DESC_OCTET_LENGTH_PTR | Supported |
| SQL_DESC_PARAMETER_TYPE | Only input parameters |
| SQL_DESC_PRECISION | Supported |
| SQL_DESC_SCALE | Supported |
| SQL_DESC_SCHEMA_NAME | Not supported |
| SQL_DESC_SEARCHABLE | Supported |
| SQL_DESC_TABLE_NAME | Not supported |
| SQL_DESC_TYPE | Supported |
| SQL_DESC_TYPE_NAME | Supported |
| SQL_DESC_UNNAMED | Supported |
| SQL_DESC_UNSIGNED | Supported |
| SQL_DESC_UPDATABLE | Supported |