OpenSchema

Syntax

Set rsobject = connectionobject.OpenSchema(QueryType[, Criteria][, SchemaID])

Description

Returns descriptive schema information from the provider about the data source.

The OpenSchema method returns a read-only RecordSet object that contains schema (which means self-descriptive) information about the data source. For example, schema information can include the names of the tables, the names of the columns in the tables, and the data type of each column.

There is one mandatory parameter and two optional parameters.

Parameter	Description
QueryType	The mandatory QueryType parameter is one of the SchemaEnum constants that describes the type of schema to use. There are 41 types of these SchemaEnum values to choose from. However, OLE DB specifications only require that three of these possibilities be supported. They are, adSchemaColumns, adSchemaProviderTypes, and adSchemaTables. Further, the provider is not required by OLE DB to support the Constraint Columns values imposed by the optional Criteria parameter (discussed below) for these three schemas.
Criteria	The optional Criteria parameter is a variant composed of an array of query constraints for each of the values in the SchemaEnum constants. These are called Constraint Columns and they set limits to the results obtained using a schema query.
SchemaID	The SchemaID parameter is required if the QueryType parameter is set to the adSchemaProviderSpecific constant. This indicates that the query is a provider schema that is not defined by OLE DB specifications.

SchemaEnum Constants

Constant	Value	Description
adSchemaColumns	4	Request column information
adSchemaProviderTypes	22	Request provider type information
adSchemaTables	20	Request table information

SchemaEnum Constants and Constraint Columns Values

Constant	Value	Description	Constraint Columns
adSchemaAsserts	0	Returns the assertions	CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME
adSchemaCatalogs	1	Returns the catalog information	CATALOG_NAME
adSchemaCharacterSets	2	Returns the defined character set in the catalog	CHARACTER_SET_CATALOG CHARACTER_SET_SCHEMA CHARACTER_SET_NAME
adSchemaCheckConstraints	5	Returns the defined check constraints in the catalog	CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME
adSchemaCollations	3	Returns the defined character collations in the catalog	COLLATION_CATALOG COLLATION_SCHEMA COLLATION_NAME
adSchemaColumnDomainUsage	11	Returns the columns that are domain dependent	DOMAIN_CATALOG DOMAIN_SCHEMA DOMAIN_NAME COLUMN_NAME
adSchemaColumnPrivileges	13	Returns the column privilege information	TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME GRANTOR GRANTEE
adSchemaColumns	4	Returns the columns information	TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME
adSchemaConstraintColumnUsage	6	Returns the columns used by constraints	COLUMN_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME
adSchemaConstraintTableUsage	7	Returns the tables used by constraints	TABLE_CATALOG TABLE_SCHEMA TABLE_NAME
adSchemaCubes	32	Returns info about the cubes used for multi-dimensional data	CATALOG_NAME SCHEMA_NAME CUBE_NAME
adSchemaDBInfoKeywords	30	Return the keywords recognized by the provider	none
adSchemaDBInfoLiterals	31	Return the literals used in text commands by the provider	none
adSchemaDimensions	33	Returns info about the dimensions in a cube	CATALOG_NAME SCHEMA_NAME CUBE_NAME DIMENSION_NAME DIMENSION_UNIQUE_NAME
adSchemaForeignKeys	27	Returns the foreign key column	PK_TABLE_CATALOG PK_TABLE_SCHEMA PK_TABLE_NAME FK_TABLE_CATALOG FK_TABLE_SCHEMA FK_TABLE_NAME
adSchemaHierarchies	34	Returns hierarchy info for multi-dimensional data	CATALOG_NAME SCHEMA_NAME CUBE_NAME DIMENSION_UNIQUE_NAME HIERARCHY_NAME HIERARCHY_UNIQUE_NAME
adSchemaIndexes	12	Returns the indexes defined in a catalog	TABLE_CATALOG TABLE_SCHEMA INDEX_NAME TYPE TABLE_NAME
adSchemaKeyColumnUsage	8	Returns the defined key columns in the catalog	COLUMN_NAME CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME
adSchemaLevels	35	Returns info about the levels in multi-dimensional data	CATALOG_NAME SCHEMA_NAME CUBE_NAME DIMENSION_UNIQUE_NAME HIERARCHY_UNIQUE_NAME LEVEL_NAME LEVEL_UNIQUE_NAME
adSchemaMeasures	36	Returns the measures for multi-dimensional data	CATALOG_NAME SCHEMA_NAME CUBE_NAME MEASURE_NAME MEASURE_UNIQUE_NAME
adSchemaMembers	38	Returns the available members for multi-dimensional data	CATALOG_NAME SCHEMA_NAME CUBE_NAME DIMENSION_UNIQUE_NAME HIERARCHY_UNIQUE_NAME LEVEL_UNIQUE_NAME LEVEL_NUMBER MEMBER_NAME MEMBER_UNIQUE_NAME MEMBER_CAPTION MEMBER_TYPE TREE OPERATOR
adSchemaPrimaryKeys	28	Returns the primary key columns	PK_TABLE_CATALOG PK_TABLE_SCHEMA PK_TABLE_NAME
adSchemaProcedureColumns	29	Returns info on columns returned by stored procedures	PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME COLUMN_NAME
adSchemaProcedureParameters	26	Returns info on the parameters and return codes of stored procedures	PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME PARAMETER_NAME
adSchemaProcedures	16	Returns info on the stored procedures	PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME PROCEDURE_TYPE
adSchemaProperties	37	Returns info on the properties of each level of multi-dimensional data	CATALOG_NAME SCHEMA_NAME CUBE_NAME DIMENSION_UNIQUE_NAME HIERARCHY_UNIQUE_NAME LEVEL_UNIQUE_NAME MEMBER_UNIQUE_NAME PROPERTY_TYPE PROPERTY_NAME
adSchemaProviderSpecific	-1	For provider-specific, non-standard schema	provider specfic
adSchemaProviderTypes	22	Returns the provider-supported data types	DATA_TYPE BEST_MATCH
adSchemaReferentialConstraints	9	Returns the defined referential constraints in the catalog	CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME
adSchemaSchemata	17	Returns the schema owned by a user	CATALOG_NAME SCHEMA_NAME SCHEMA_OWNER
adSchemaSQLLanguages	18	Returns the SQL language support info	none
adSchemaStatistics	19	Returns the defined statistics in a catalog	TABLE_CATALOG TABLE_SCHEMA TABLE_NAME
adSchemaTableConstraints	10	Returns the table contraints defined in the catalog	CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME CONSTRAINT_TYPE
adSchemaTablePrivileges	14	Returns the privileges on tables	TABLE_CATALOG TABLE_SCHEMA TABLE_NAME GRANTOR GRANTEE
adSchemaTables	20	Returns the tables in a catalog	TABLE_CATALOG TABLE_SCHEMA TABLE_NAME TABLE_TYPE
adSchemaTranslations	21	Returns the character set translation info	TRANSLATION_CATALOG TRANSLATION_SCHEMA TRANSLATION_NAME
adSchemaTrustees	39	Not used	none
adSchemaUsagePrivileges	15	Returns the user privilege info	OBJECT_CATALOG OBJECT_SCHEMA OBJECT_NAME OBJECT_TYPE GRANTOR GRANTEE
adSchemaViewColumnUsage	24	Returns the column usage for viewed tables	VIEW_CATALOG VIEW_SCHEMA VIEW_NAME
adSchemaViews	23	Returns the views info from the catalog	TABLE_CATALOG TABLE_SCHEMA TABLE_NAME
adSchemaViewTableUsage	25	Returns the table usage for viewed tables	VIEW_CATALOG VIEW_SCHEMA VIEW_NAME

See Also

Connection, Open, Record.Open, Recordset.Open, Stream.Open.

Example

Set objRecordset = objConnection.OpenSchema(adSchemaTables)