• New Coverage of Visual Basic 4.0 Features for Database Developers

What's New in This Edition

New Coverage of Visual Basic 4.0 Features for Database Developers

Here's a list of the most important new features of Visual Basic 4.0 that are of interest to database developers, primarily related to the Jet database engine in 16-bit and 32-bit database front-ends:

• The Jet 3.0 database engine, which optimizes the performance of new 32-bit Visual Basic 4.0 database front-ends.
  
  
• Two 32-bit DAO TypeLibs for the 32-bit version of Visual Basic 4.0. The Microsoft DAO 2.5/3.0 Compatibility Library is designed to provide backward compatibility with existing 16-bit Visual Basic 3.0 database code written to DAO 2.0 or 2.5. The Microsoft DAO 3.0 Object Library requires that you obey new Jet 3.0 syntax rules.
  
  
• Capability of the 16-bit version of Visual Basic to create a VBA reference to the 16-bit version of the Jet 2.5 TypeLib, called the Microsoft DAO 2.5 Object Library (version 2.5), which implements all of the object subclasses of the Jet 2.5 DAO, together with the properties of and methods applicable to each of the DAO's member objects.
  
  
• 16-bit and 32-bit data-aware grid, list box, and combo box OLE Controls that you can bind to the DAO's new Recordset object.
  
  
• Improved query performance against large tables with Rushmore optimization borrowed from Microsoft FoxPro. Depending on the size of your tables and the complexity of your queries, you can gain a ten-fold or better speed increase, and Jet 3.0 speeds up indexing by about a factor of 10.
  
  
• SQL Data Definition Language (DDL) statements for creating databases, tables, and indexes. The DAO provides new Users and Groups collections for managing database security with VBA and the Relations collection for enforcing referential integrity.
  
  
• Multiple Workspace objects, each representing an instance of the Jet 3.0 engine, support their own set of security objects, have separate transaction spaces, and can execute interlaced multiple transactions.
  
  
• ODBC support for multiple result sets from client/server queries, improved error reporting, and enhanced SQL Server performance with the new 32-bit ODBC 2.5 driver.
  
  
• A new Recordset object that replaces Visual Basic 3.0's Table, Dynaset, and Snapshot objects.
  
  
• The 32-bit Remote Data Object (RDO) and Remote Data Control (RDC) of the Enterprise Edition of Visual Basic 4.0 substitute a "thin layer over ODBC" to speed queries against client/server RDBMSs. The RDO permits asynchronous query execution and expands Visual Basic 4.0's capability to handle complex server stored procedures.