Metodo ADO OpenSchema
❮ Completare il riferimento all'oggetto di connessione
Il metodo OpenSchema restituisce un oggetto Recordset con informazioni sullo schema del provider sull'origine dati. Ad esempio, le informazioni sullo schema possono includere i nomi delle tabelle, i nomi delle colonne nelle tabelle e il tipo di dati di ciascuna colonna. Il recordset verrà aperto come recordset di sola lettura.
Sintassi
Set rs=objconn.OpenSchema(querytype,criteria,schemaid)
Parameter | Description |
---|---|
querytype | Required. A SchemaEnum
value that represents the type of schema query to run Note: The OLEDB specification only require 3 of the SchemaEnum values to be supported. These are adSchemaTables, adSchemaColumns, and the adSchemaProviderTypes |
criteria | Optional. An array of query constraints for each querytype option, as listed in SchemaEnum |
schemaid | The GUID for a provider-schema query not defined by the OLE DB specification. Required if querytype is set to adSchemaProviderSpecific |
Valori SchemaEnum
Constant | Value | Description | Constraint Columns |
---|---|---|---|
adSchemaProviderSpecific | -1 | Used if the provider defines its own nonstandard schema queries | Provider specific |
adSchemaAsserts | 0 | Returns the assertions defined in the catalog | CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME |
adSchemaCatalogs | 1 | Returns the physical attributes associated with catalogs accessible from the DBMS | CATALOG_NAME |
adSchemaCharacterSets | 2 | Returns the character sets defined in the catalog | CHARACTER_SET_CATALOG CHARACTER_SET_SCHEMA CHARACTER_SET_NAME |
adSchemaCollations | 3 | Returns the character collations defined in the catalog | COLLATION_CATALOG COLLATION_SCHEMA COLLATION_NAME |
adSchemaColumns | 4 | Returns the columns of tables defined in the catalog | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME |
adSchemaCheckConstraints | 5 | Returns the check constraints defined in the catalog | CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME |
adSchemaConstraintColumnUsage | 6 | Returns the columns used by referential constraints, unique constraints, check constraints, and assertions, defined in the catalog | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME |
adSchemaConstraintTableUsage | 7 | Returns the tables that are used by referential constraints, unique constraints, check constraints, and assertions defined in the catalog | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME |
adSchemaKeyColumnUsage | 8 | Returns the columns defined in the catalog that are constrained as keys | CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME |
AdSchemaReferentialConstraints | 9 | Returns the referential constraints defined in the catalog | CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME |
adSchemaTableConstraints | 10 | Returns the table constraints defined in the catalog | CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME TABLE_CATALOG TABLE_SCHEMA TABLE_NAME CONSTRAINT_TYPE |
adSchemaColumnsDomainUsage | 11 | Returns the columns defined in the catalog that are dependent on a domain defined in the catalog | DOMAIN_CATALOG DOMAIN_SCHEMA DOMAIN_NAME COLUMN_NAME |
adSchemaIndexes | 12 | Returns the indexes defined in the catalog | TABLE_CATALOG TABLE_SCHEMA INDEX_NAME TYPE TABLE_NAME |
adSchemaColumnPrivileges | 13 | Returns the privileges on columns of tables defined in the catalog | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME COLUMN_NAME GRANTOR GRANTEE |
adSchemaTablePrivileges | 14 | Returns the privileges on tables defined in the catalog | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME GRANTOR GRANTEE |
adSchemaUsagePrivileges | 15 | Returns the USAGE privileges on objects defined in the catalog | OBJECT_CATALOG OBJECT_SCHEMA OBJECT_NAME OBJECT_TYPE GRANTOR GRANTEE |
adSchemaProcedures | 16 | Returns the procedures defined in the catalog | PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME PROCEDURE_TYPE |
adSchemaSchemata | 17 | Returns the schemas (database objects) | CATALOG_NAME SCHEMA_NAME SCHEMA_OWNER |
adSchemaSQLLanguages | 18 | Returns the conformance levels, options, and dialects supported by the SQL-implementation processing data defined in the catalog. | None |
adSchemaStatistics | 19 | Returns the statistics defined in the catalog | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME |
adSchemaTables | 20 | Returns the tables defined in the catalog that are accessible | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME TABLE_TYPE |
adSchemaTranslations | 21 | Returns the character translations defined in the catalog that are accessible | TRANSLATION_CATALOG TRANSLATION_SCHEMA TRANSLATION_NAME |
adSchemaProviderTypes | 22 | Returns the data types supported by the data provider | DATA_TYPE BEST_MATCH |
adSchemaViews | 23 | Returns the views defined in the catalog that are accessible | TABLE_CATALOG TABLE_SCHEMA TABLE_NAME |
adSchemaViewColumnUsage | 24 | Returns the columns on which viewed tables, are dependent | VIEW_CATALOG VIEW_SCHEMA VIEW_NAME |
adSchemaViewTableUsage | 25 | Returns the tables on which viewed tables, are dependent | VIEW_CATALOG VIEW_SCHEMA VIEW_NAME |
adSchemaProcedureParameters | 26 | Returns info about the parameters and return codes of procedures | PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME PARAMETER_NAME |
adSchemaForeignKeys | 27 | Returns the foreign key columns defined in the catalog | PK_TABLE_CATALOG PK_TABLE_SCHEMA PK_TABLE_NAME FK_TABLE_CATALOG FK_TABLE_SCHEMA FK_TABLE_NAME |
adSchemaPrimaryKeys | 28 | Returns the primary key columns defined in the catalog | PK_TABLE_CATALOG PK_TABLE_SCHEMA PK_TABLE_NAME |
adSchemaProcedureColumns | 29 | Returns info about the columns of rowsets returned by procedures | PROCEDURE_CATALOG PROCEDURE_SCHEMA PROCEDURE_NAME COLUMN_NAME |
adSchemaDBInfoKeywords | 30 | Returns a list of provider-specific keywords | None |
adSchemaDBInfoLiterals | 31 | Returns a list of provider-specific literals used in text commands | None |
adSchemaCubes | 32 | Returns info about the available cubes in a schema | CATALOG_NAME SCHEMA_NAME CUBE_NAME |
adSchemaDimensions | 33 | Returns info about the dimensions in a given cube | CATALOG_NAME SCHEMA_NAME CUBE_NAME DIMENSION_NAME DIMENSION_UNIQUE_NAME |
adSchemaHierarchies | 34 | Returns info about the hierarchies available in a dimension | CATALOG_NAME SCHEMA_NAME CUBE_NAME DIMENSION_UNIQUE_NAME HIERARCHY_NAME HIERARCHY_UNIQUE_NAME |
adSchemaLevels | 35 | Returns info about the levels available in a dimension | CATALOG_NAME SCHEMA_NAME CUBE_NAME DIMENSION_UNIQUE_NAME HIERARCHY_UNIQUE_NAME LEVEL_NAME LEVEL_UNIQUE_NAME |
adSchemaMeasures | 36 | Returns info about the available measures | CATALOG_NAME SCHEMA_NAME CUBE_NAME MEASURE_NAME MEASURE_UNIQUE_NAME |
adSchemaProperties | 37 | Returns info about the available properties for each level of the dimension | CATALOG_NAME SCHEMA_NAME CUBE_NAME DIMENSION_UNIQUE_NAME HIERARCHY_UNIQUE_NAME LEVEL_UNIQUE_NAME MEMBER_UNIQUE_NAME PROPERTY_TYPE PROPERTY_NAME |
adSchemaMembers | 38 | Returns info about the available members | 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 |
adSchemaTrustees | 39 | For future use | None |
❮ Completare il riferimento all'oggetto di connessione