OleDbSchemaGuid::Key_Column_Usage Field
Returns the columns defined in the catalog that is constrained as keys by a given user.
Assembly: System.Data (in System.Data.dll)
Key_Column_Usage maps to the OLE DB KEY_COLUMN_USAGE rowset. Unless otherwise specified, restriction columns are returned in the following order.
Restriction column | CLR data type | Description |
|---|---|---|
CONSTRAINT_CATALOG | string | Catalog name. A null value if the provider does not support catalogs. |
CONSTRAINT_SCHEMA | string | Unqualified schema name. A null value if the provider does not support schemas. |
CONSTRAINT_NAME | string | Constraint name. |
TABLE_CATALOG | string | Catalog name in which the table containing the key column is defined. A null value if the provider does not support catalogs. |
TABLE_SCHEMA | string | Unqualified schema name in which the table containing the key column is defined. A null value if the provider does not support schemas. |
TABLE_NAME | string | Table name containing the key column. |
COLUMN_NAME | string | Name of the column participating in the unique, primary, or foreign key. This column, together with the COLUMN_GUID and COLUMN_PROPID columns, forms the column ID. One or more of these columns will be a null value, depending on which elements of the DBID structure the provider uses. (DBID is a formal structure serialized into the COLUMN_NAME column of the COLUMN_DOMAIN_USAGE rowset.) |
Available since 1.1