Introduction

The XSB-ODBC interface is subsystem that allows XSB users to access databases through ODBC connections. This is mostly of interest to Microsoft Windows users. The interface allows XSB users to access data in any ODBC compliant database management system (DBMS). Using this uniform interface, information in different DBMS's can be accessed as though it existed as Prolog facts. The XSB-ODBC interface provides users with three levels of interaction: an SQL level, a relation level and a view level. The SQL level allows users to write explicit SQL statements to be passed to the interface to retrieve data from a connected database. The relation level allows users to declare XSB predicates that connect to individual tables in a connected database, and which when executed support tuple-at-a-time retrieval from the base table. The view level allows users to use a complex XSB query, including conjuction, negation and aggregates, to specify a database query. A listing of the features that the XSB-ODBC interface provides is as follows:

• Concurrent access from multiple XSB processes to a single DBMS
• Access from a single XSB process to multiple ODBC DBMS's
• Full data access and cursor transparency including support for
  • Full data recursion through XSB's tabling mechanism (depending on the capabilities of the underlying ODBC driver.
  • Runtime type checking
  • Automatic handling of NULL values for insertion, deletion and querying
• Full access to data source including
  • Transaction support
  • Cursor reuse for cached SQL statements with bind variables (thereby avoiding re-parsing and re-optimizing).
  • Caching compiler generated SQL statements with bind variables and efficient cursor management for cached statements
• A powerful Prolog / SQL compiler based on [8].
• Full source code availability
• Independence from database schema by the relation level interface
• Performance as SQL by employing a view level
• No mode specification is required for optimized view compilation

We use the Hospital database as our example to illustrate the usage of XSB-ODBC interface in this manual. We assume the basic knowledge of Microsoft ODBC interface and its ODBC administrator throughout the text. Please refer to ``Inside Windows^TM 95'' (or more recent documentation) for information on this topic.