Consumers can get information about a data source without knowing its structure by using the IDBSchemaRowset methods.
This schema defines a minimum content of the system schema. It is assumed that consumers will precompile and store specialized queries, such as those for command planning and execution-time plan validation, and that storage engines may have specialized optimizations associated with those plans. Consumers can also look at the schema tables in the schema, and thus discover other schema tables and attributes beyond the minimum set.
For information about the schema rowsets, see Appendix B, “Schema Rowsets,” in this document. This provider returns all of the columns in the rowsets returned. This information may be NULL. Provider-specific columns described in Appendix B are returned after the last column defined by OLE DB.
Schema rowsets are identified by GUIDs. The following table lists these GUIDs and the columns for which restrictions can be specified on the schema rowset. The number of restriction columns for each schema rowset are defined as constants prefixed with CRESTRICTIONS_ in the header files. Restriction values are treated as literals rather than as search patterns. For example, the restriction value “A_C” matches “A_C” but not “ABC.”
| GUID | Number of restrictions | Restriction columns |
| DBSCHEMA_ASSERTIONS | 3 | CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME |
| DBSCHEMA_CATALOG | 1 | CATALOG_NAME |
| DBSCHEMA_CHARACTER_SETS | 3 | CHARACTER_SET_CATALOG CHARACTER_SET_SCHEMA CHARACTER_SET_NAME |
| DBSCHEMA_CHECK_CONSTRAINTS | 3 | CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME |
| DBSCHEMA_COLLATIONS | 3 | COLLATION_CATALOG COLLATION_SCHEMA COLLATION_NAME |
| DBSCHEMA_COLUMN_DOMAIN_USAGE | 4 | DOMAIN_CATALOG DOMAIN_SCHEMA DOMAIN_NAME COLUMN_NAME |
| DBSCHEMA_COLUMN_PRIVILEGES | 6 | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME GRANTOR GRANTEE |
| DBSCHEMA_COLUMNS | 4 | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME |
| DBSCHEMA_CONSTRAINT_COLUMN_USAGE | 4 | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME |
| DBSCHEMA_CONSTRAINT_TABLE_USAGE | 3 | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME |
| DBSCHEMA_FOREIGN_KEYS | 6 | PK_TABLE_CATALOG PK_TABLE_SCHEMA PK_TABLE_NAME FK_TABLE_CATALOG FK_TABLE_SCHEMA FK_TABLE_NAME |
| DBSCHEMA_INDEXES | 5 | TABLE_CATALOG TABLE_SCHEMA INDEX_NAME TYPE TABLE_NAME |
| DBSCHEMA_KEY_COLUMN_USAGE | 7 | CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME |
| DBSCHEMA_PRIMARY_KEYS | 3 | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME |
| DBSCHEMA_PROCEDURE_COLUMNS | 4 | PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME COLUMN_NAME |
| DBSCHEMA_PROCEDURE_PARAMETERS | 4 | PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME PROCEDURE_TYPE |
| DBSCHEMA_PROVIDER_TYPES | 2 | DATA_TYPE BEST_MATCH |
| DBSCHEMA_REFERENTIAL_CONSTRAINTS | 3 | CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME |
| DBSCHEMA_SCHEMATA | 3 | CATALOG_NAME SCHEMA_NAME SCHEMA_OWNER |
| DBSCHEMA_SQL_LANGUAGES | 0 | NONE |
| DBSCHEMA_STATISTICS | 3 | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME |
| DBSCHEMA_TABLE_CONSTRAINTS | 7 | CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME CONSTRAINT_TYPE |
| DBSCHEMA_TABLE_PRIVILEGES | 5 | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME GRATOR GRANTEE |
| DBSCHEMA_VIEW_COLUMN_USAGE | 3 | VIEW_CATALOG VIEW_SCHEMA VIEW_NAME |
| DBSCHEMA_VIEW_TABLE_USAGE | 3 | VIEW_CATALOG VIEW_SCHEMA VIEW_NAME |
| DBSCHEMA_VIEWS | 3 | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME |
For a list of supported schema rowsets, see Appendix B.
| Method | Description |
| GetRowset | Returns a schema rowset. |
| GetSchemas | Returns a list of schema rowsets accessible by IDBSchemaRowset::GetRowset. |
Returns a schema rowset. For information on how this interface is implemented, see the OLE DB Programmer’s Reference. For information about the rowset property set, see Appendix A. For more information about the schema rowsets supported, see Appendix B.
Returns a list of schema rowsets accessible by IDBSchemaRowset::GetRowset. For information on how this interface is implemented, see the OLE DB Programmer’s Reference.