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There are four leading client-server development packages in the Windows environment: Borland's Delphi Client/Server Suite version 2.0; Microsoft's Visual Basic Enterprise Edition version 4.0; Powersoft's PowerBuilder Enterprise version 4.0; and, Centura Software's SQLWindows version 5.0 (Centura was formerly known as Gupta). All except SQLWindows offer 32-bit and 16-bit capability in the same package.
These products allow developers to design forms with which users can access and manipulate data in a client-server environment, and design reports based on data in a client-server environment. They all include programming languages to supplement the visual design tools. Although intended primarily for working with data on a remote server, each product includes a local database engine so that users can develop prototype applications locally before deployment.
Development environment. Each product has a distinctive environment in which developers do their work. Since this is the interface with which developers will spend most of their time, the quality of implementation has a direct impact on productivity. PowerBuilder offers a series of interfaces called 'painters,' including the Window Painter for designing forms and the DataWindow Painter for defining visual interfaces to databases. PowerBuilder's interfaces are the most intuitive and user-friendly, although the need to move between the Window Painter and DataWindow Painter can be inconvenient.
Visual Basic's and Delphi's interfaces are similar to one another. A new project begins with a blank form, on which developers place controls selected from a palette. They set properties for the form as a whole or for individual controls by entering options in a property grid, and they access the program editor by double-clicking on the component for which they want to write code.
SQLWindows developers work in an interface called Outliner, essentially a program editor in which developers can drill down to varying levels of detail. Outliner lists the components making up all applications, and any sub-components, in outline form. Code is related to specific components at their associated levels in the outline.
Database access. In order for applications to access data in a client-server environment, there must be software available to connect to the specific database format in use. Visual Basic uses Microsoft's Open DatabaseConnectivity (ODBC) for database access. The other products support ODBC, but also provide their own drivers for direct access to specific...