Visual DataFlex is now !

This website, VisualDataFlex.com, is being retired, and will eventually be shut down.
Please visit DataAccess.com for the latest DataFlex product information.




Visual DataFlex and SQL Database Servers

Microsoft SQL Server Connectivity Kit for Visual DataFlex Windows and Web and DataFlex Character Mode applications.Visual DataFlex’s architecture is designed for building Windows and web applications, web services and service oriented architecture (SOA) using SQL-based DBMS servers such as Microsoft SQL Server, IBM DB2, Pervasive.SQL, Oracle and ODBC data sources.

IBM DB2 Database Connectivity Kit for Visual DataFlex Windows and Web and DataFlex Character Mode applications.The goal of the design is to provide an efficient, easy to use, easy to maintain development environment that is largely database independent.

Visual DataFlex’s embedded database can be used as a workgroup alternative to servers such as Microsoft SQL Server, IBM DB2, Peversaive.SQL, Oracle, MySQL, and ODBC data sources.

For each database table used in an application, a Visual DataFlex Data Dictionary Object ("DDO") is created.  All communication with the table is processed by the "DDO".  It manages database logic, referential integrity, business rules, validations and more.  The advantage of this architecture is that all database operations, regardless of the type of user interface or platform (rich Windows client, web browser or web service), are managed in a single place in the application development environment.

Visual DataFlex DDO’s communicate with an abstract database API that is independent of any particular database. Visual DataFlex "Connectivity Kits" (called "adaptors" or "drivers" in other environments) link the database API to the preferred server or database environment.

All database updates within a Data Dictionary occur within a transaction. When a save occurs an entire hierarchy of records may be created, updated and saved. When a delete occurs it is possible that many records, from many child tables will be deleted and that many parent table records will be updated. Both of these operations occur within a single transaction. If for any reason a transaction cannot be completed, the entire transaction is rolled back and no changes are committed to the database.

The Connectivity Kits contain the intelligence to apply a lock appropriate to the target database. Managing transactions, locking and multi-user access is automatic requiring no specific programming by the developer.  For some databases, such as Microsoft SQL and Pervasive.SQL, the Connectivity Kit will lock only the records involved in the current transaction.  For others, such as the embedded database, the lock is applied to an entire table until a transaction is complete.  In either case, no database-specific coding is required from the application developer - the Visual DataFlex design, architecture, Data Dictionaries, database API and Connectivity Kits will execute the correct logic for the database in use.

Multi-segment relationships are enabled for SQL database servers and in the embedded database. This helps developers build applications that model real-world data and easily make connections to SQL databases that have multi-segment relationships. 

Alphanumeric primary keys in database tables are supported. Most database servers allow Primary Keys to be alphanumeric. This feature enables Visual DataFlex and Web Application Server applications to connect to a database provided that there is a defined alphanumeric or numeric Primary Key. Recnum support is still provided for compatibility with existing, embedded database applications. 

Application workspaces support a default database connection. This allows tools such as Studio and Database Builder to do more things automatically, more often. For example, if the database used for a particular workspace is Microsoft SQL Server, Database Builder will customize dialogs that deal with the database to be specific to Microsoft SQL, instead of displaying generic connectity information or forcing the user having to specify the database for each task.

Database Builder’s Connectivity Wizards help developers quickly and easily connect to SQL servers. 

Back

Download Visual DataFlex | Subscribe | Contact