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FOREIGN_KEYS Rowset

GUID: DBSCHEMA_FOREIGN_KEYS

Number of restriction columns: 6

Restriction columns: PK_TABLE_CATALOG, PK_TABLE_SCHEMA, PK_TABLE_NAME, FK_TABLE_CATALOG, FK_TABLE_SCHEMA, FK_TABLE_NAME

Default sort order: FK_TABLE_CATALOG, FK_TABLE_SCHEMA, FK_TABLE_NAME

Description: The FOREIGN_KEYS rowset identifies the foreign key columns defined in the catalog by a given user. This schema rowset is built upon several SQL-92 schema views as a convenience to the non-SQL programmer, and if supported, this must be synchronized with the related SQL-92 views (REFERENTIAL_CONSTRAINTS and CONSTRAINT_COLUMN_USAGE).

Column name

Type indicator

Description

PK_TABLE_CATALOG

DBTYPE_WSTR

Catalog name in which the primary key table is defined. NULL if the provider does not support catalogs.

PK_TABLE_SCHEMA

DBTYPE_WSTR

Unqualified schema name in which the primary key table is defined. NULL if the provider does not support schemas.

PK_TABLE_NAME

DBTYPE_WSTR

Primary key table name.

PK_COLUMN_NAME

DBTYPE_WSTR

Primary key column name. This column, together with the PK_COLUMN_GUID and PK_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.

PK_COLUMN_GUID

DBTYPE_GUID

Primary key column GUID.

PK_COLUMN_PROPID

DBTYPE_UI4

Primary key column property ID.

FK_TABLE_CATALOG

DBTYPE_WSTR

Catalog name in which the foreign key table is defined. NULL if the provider does not support catalogs.

FK_TABLE_SCHEMA

DBTYPE_WSTR

Unqualified schema name in which the foreign key table is defined. NULL if the provider does not support schemas.

FK_TABLE_NAME

DBTYPE_WSTR

Foreign key table name.

FK_COLUMN_NAME

DBTYPE_WSTR

Foreign key column name. This column, together with the FK_COLUMN_GUID and FK_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.

FK_COLUMN_GUID

DBTYPE_GUID

Foreign key column GUID.

FK_COLUMN_PROPID

DBTYPE_UI4

Foreign key column property ID.

ORDINAL

DBTYPE_UI4

The order of the column names (and GUIDs and property IDs) in the key. For example, a table might contain several foreign key references to another table. The ordinal starts over for each reference; for example, two references to a three-column key would return 1, 2, 3, 1, 2, 3.

UPDATE_RULE

DBTYPE_WSTR

If an <update rule> was specified, then the UPDATE_RULE value is one of the following:

"CASCADE" ? A <referential action> of CASCADE was specified.

"SET NULL" ? A <referential action> of SET NULL was specified.

"SET DEFAULT" ? A <referential action> of SET DEFAULT was specified.

"NO ACTION" ? A <referential action> of NO ACTION was specified.

Providers should return NULL only if they cannot determine the UPDATE_RULE. In most cases, this implies a default of NO ACTION.

DELETE_RULE

DBTYPE_WSTR

If a <delete rule> was specified, the DELETE_RULE value is one of the following:

"CASCADE" ? A <referential action> of CASCADE was specified.

"SET NULL" ? A <referential action> of SET NULL was specified.

"SET DEFAULT" ? A <referential action> of SET DEFAULT was specified.

"NO ACTION" ? A <referential action> of NO ACTION was specified.

Providers should return NULL only if they cannot determine the DELETE_RULE. In most cases, this implies a default of NO ACTION.

PK_NAME

DBTYPE_WSTR

Primary key name. NULL if the provider does not support named primary key constraints. This column is not returned by 1.x providers.

FK_NAME

DBTYPE_WSTR

Foreign key name. NULL if the provider does not support named foreign key constraints. This column is not returned by 1.x providers.

DEFERRABILITY

DBTYPE_I2

Deferrability of the foreign key. Value is one of the following:

DBPROPVAL_DF_INITIALLY_DEFERRED

DBPROPVAL_DF_INITIALLY_IMMEDIATE

DBPROPVAL_DF_NOT_DEFERRABLE

This column is not returned by 1.x providers.