Update of .NET Provider for OLE DB. Support of schemas implemented

We continue to develop our .NET Provider for OLE DB. In the new build (#1434), we have implemented the methods to obtain database metadata:

• OleDbConnection.GetOleDbSchemaTable
• OleDbConnection.GetSchema

GetOleDbSchemaTable

Supported schemas:

• SchemaGuids
• DbInfoKeywords
• DbInfoLiterals
• All schemas of the OLE DB Provider

Distinctions compared to standard OLEDB.NET Provider:

• The SchemaGuids schema describes all schemas including SchemaGuids, DbInfoKeywords and DbInfoLiterals.
• The SchemaGuids schema supports restrictions for the Schema column.

GetSchema

Supported schemas:

• MetaDataCollections
• Restrictions
• DataTypes
• ReservedWords
• DataSourceInformation
• CharacterSets
• Collations
• Tables
• Views
• Columns
• Procedures
• ProcedureParameters
• ProcedureColumns
• Indexes

Distinctions compared to standard OLEDB.NET Provider:

• The MetaDataCollections schema supports restrictions for the column CollectionName.
• The Restrictions schema supports restrictions for the columns CollectionName and RestrictionName.
• More accurate population of the DataSourceInformation schema.
• More accurate population of the Restrictions schema.

Implementation peculiarities

• Caching of data from its own schemas (SchemaGuids, DbInfoKeywords, DbInfoLiterals, …).
• Coherence of information from metadata schemas with the descriptions of the resulting rowset columns and command parameters (ensured by IBProvider).
• Different algorithms of metadata loading for InterBase and Firebird. Including — our provider takes into account the version of the server and the version of database ODS (ensured by IBProvider).
• Caching of OLE DB metadata schemas is carried out on the IBProvider level (see a property «schema_cache»).

Other changes

• The OleDbSchemaGuid class added with the lists of known OLE DB schema identifiers.
• The OleDbSchemaRestriction class added with the lists of restriction indexes for known OLE DB schemas.
• The OleDbLiteral class added.
• The OleDbMetaDataCollectionNames class added.
• The number of tests and debug structures ensuring the correct work of components increased.

New examples

If you are interested in working with stored procedures grouped into PACKAGE, please take a look at the new example for our .NET Provider:

• Creation and working with PACKAGE (C#, FB3)