The PRIMARY_KEYS rowset identifies the primary key columns defined in the catalog by a given user. This schema rowset is built upon an SQL92 schema view as a convenience to the non-SQL programmer, and, if supported, must be synchronized with the related SQL92 view (CONSTRAINT_COLUMN_USAGE).
The PRIMARY_KEYS rowset contains the following columns.
| Column name | Type indicator | Description |
| PK_NAME | DB_WSTR | Primary key name. NULL if the provider does not support primary key constraints. This column is not returned by 1.x providers. |
| TABLE_CATALOG | DBTYPE_WSTR | Catalog name in which the table is defined. NULL if the provider does not support catalogs. |
| TABLE_SCHEMA | DBTYPE_WSTR | Unqualified schema name in which the table is defined. NULL if the provider does not support schemas. |
| TABLE_NAME | DBTYPE_WSTR | Table name. |
| COLUMN_NAME | DBTYPE_WSTR | Primary key column name. This column, together with the COLUMN_GUID and COLUMN_PROPID columns, forms the column ID. One or more of these columns will be NULL depending on which elements of the DBID structure the provider uses. |
| COLUMN_GUID | DBTYPE_GUID | Primary key column GUID. |
| COLUMN_PROPID | DBTYPE_UI4 | Primary key column property ID. |
| ORDINAL | DBTYPE_UI4 | The order of the column names (and GUIDs and property IDs) in the key. |
Default Sort Order: TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME