The CONSTRAINT_COLUMN_USAGE rowset identifies the columns used by referential constraints, unique constraints, check constraints, and assertions, defined in the catalog and owned by a given user.
The CONSTRAINT_COLUMN_USAGE rowset contains the following columns.
| Column name | Type indicator | Description |
| 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 | 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 | Column GUID. |
| COLUMN_PROPID | DBTYPE_UI4 | Column property ID. |
| CONSTRAINT_CATALOG | DBTYPE_WSTR | Catalog name. NULL if the provider does not support catalogs. |
| CONSTRAINT_SCHEMA | DBTYPE_WSTR | Unqualified schema name. NULL if the provider does not support schemas. |
| CONSTRAINT_NAME | DBTYPE_WSTR | Constraint name. |
Default Sort Order: TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME, COLUMN_NAME, COLUMN_GUID, COLUMN_PROPID, CONSTRAINT_CATALOG, CONSTRAINT_SCHEMA, CONSTRAINT_NAME