Key Features of ActiveX Access Method
The ActiveX access method includes a number of key features to make developing applications with PSQL.
Data Source for Data-aware Controls in VB
ActiveX can be used as a data source by other data-aware controls in Visual Basic, including third-party controls such as Apex TrueGrid grid controls or Sheridan Data Widgets. The PSQL Bound Controls in Visual Basic and in other development environments.
Field-level Access
The ActiveX access method uses data dictionary files (DDFs) to provide field-level access to PSQL data. Fields can be referenced either by name or by ordinal. All PSQL field data types except LVAR are supported.
Property and Method Interface
In addition to the control objects, the ActiveX access method provides a number of properties and methods for programming convenience and flexibility. These properties and methods enable you to set up and execute a number of PSQL operations without extensive coding and to manipulate the data in code through interaction with the PSQL bound controls, the programming environment, or other third-party controls.
Extended Operations
The ActiveX access method simplifies using PSQL extended operations, which provide client/server record set caching, field selection, and record filtering capabilities.
Extended operations provide the means to minimize network traffic when running distributed applications against centralized databases, improve performance, and simplify the implementation of multi-row objects such as grid controls and record lists.
DDFs
The ActiveX access method, like the ODBC interface, requires DDFs. Use the PSQL Control Center to create a database with DDFs. See
Using PSQL Control Center
in
PSQL User's Guide
.
ActiveX DDF Access Methods
The data source includes methods for accessing DDF information from within your application code.
Remote Data Access
In addition to workstation and client/server options, the ActiveX access method can provide access to PSQL data using URIs.
Joined Tables
The Join property of the VAccess control allows you to specify that two files are to be linked by a key value, so that any changes in the record positioning of the first file will also affect the records retrieved from the second. The Join property provides a simple mechanism for browsing a relational database.