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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