Obtains database schema information from the provider.
Applies To
Required Files
msado15.dll
VC: adoint.h, adoid.h
Syntax
connection.OpenSchema (QueryType, Criteria)
| QueryType | The type of schema query to run. Can be any of the constants listed under Settings. |
| Criteria | Optional. An array of query constraints for each QueryType option, as listed under Settings. |
Settings
The QueryType argument can be any of the following enumerated constants:
| QueryType values | Description | Criteria values |
| adSchemaAsserts | 0 |
CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME |
| adSchemaCatalogs | 1 | CATALOG_NAME |
| adSchemaCharacterSets | 2 |
CHARACTER_SET_CATALOG CHARACTER_SET_SCHEMA CHARACTER_SET_NAME |
| adSchemaCheckConstraints | 5 |
CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME |
| adSchemaCollations | 3 |
COLLATION_CATALOG COLLATION_SCHEMA COLLATION_NAME |
| adSchemaColumnDomainUsage | 11 |
DOMAIN_CATALOG DOMAIN_SCHEMA DOMAIN_NAME COLUMN_NAME |
| adSchemaColumnPrivileges | 13 |
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME GRANTOR GRANTEE |
| adSchemaColumns | 4 |
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME |
| adSchemaConstraintColumnUsage | 6 |
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME |
| adSchemaConstraintTableUsage | 7 |
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME |
| adSchemaForeignKeys | 27 |
PK_TABLE_CATALOG PK_TABLE_SCHEMA PK_TABLE_NAME FK_TABLE_CATALOG FK_TABLE_SCHEMA FK_TABLE_NAME |
| adSchemaIndexes | 12 |
TABLE_CATALOG TABLE_SCHEMA INDEX_NAME TYPE TABLE_NAME |
| adSchemaKeyColumnUsage | 8 |
CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME |
| adSchemaPrimaryKeys | 28 |
PK_TABLE_CATALOG PK_TABLE_SCHEMA PK_TABLE_NAME |
| adSchemaProcedureColumns | 29 |
PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME COLUMN_NAME |
| adSchemaProcedureParameters | 26 |
PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME PARAMTER_NAME |
| adSchemaProcedures | 16 |
PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME PARAMTER_TYPE |
| adSchemaProviderTypes | 22 |
DATA_TYPE BEST_MATCH |
| adSchemaReferentialConstraints | 9 |
CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME |
| adSchemaSchemata | 17 |
CATALOG_NAME SCHEMA_NAME SCHEMA_OWNER |
| adSchemaSQLLanguages | 18 | <none> |
| adSchemaStatistics | 19 |
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME |
| adSchemaTableConstraints | 10 |
CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME CONSTRAINT_TYPE |
| adSchemaTablePrivileges | 14 |
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME GRANTOR GRANTEE |
| adSchemaTables | 20 |
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME TABLE_TYPE |
| adSchemaTranslations | 21 |
TRANSLATION_CATALOG TRANSLATION_SCHEMA TRANSLATION_NAME |
| adSchemaUsagePrivileges | 15 |
OBJECT_CATALOG OBJECT_SCHEMA OBJECT_NAME OBJECT_TYPE GRANTOR GRANTEE |
| adSchemaViewColumnUsage | 24 |
VIEW_CATALOG VIEW_SCHEMA VIEW_NAME |
| adSchemaViewTableUsage | 25 |
VIEW_CATALOG VIEW_SCHEMA VIEW_NAME |
| adSchemaViews | 23 |
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME |
Return Values
Returns a Recordset object that contains schema informaton.
Remarks
The OpenSchema method returns information about the data source, such as information about the tables on the server and the columns in the tables.
The possible queries are listed in the OLE DB reference under IDBSchemaRowset. ???Include that info here??? The Criteria argument is an array of values that can be used to limit the results of a schema query. Each schema query has a different set of parameters that it supports. The actual schemas are defined by the OLE DB specification under the “IDBSchemaRowset” interface. The ones supported in ADO 1.5 are listed above.
Providers are not required to support all the schema queries. Specifically, only adSchemaTables, adSchemaColumns and adSchemaProviderTypes are required by the OLE DB specification. However, the provider is not required to support the Criteria constraints listed above for those schema queries.
See Also
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