dbGo Overview
Go Up to Developing Database Applications
dbGo provides the developers with a powerful and logical object model for programmatically accessing, editing, and updating data from a wide variety of data sources through OLE DB system interfaces. The most common usage of dbGo is to query a table or tables in a relational database, retrieve and display the results in an application, and perhaps allow users to make and save changes to the data.
The ADO layer of an ADO-based application consists of the latest version of Microsoft ADO, an OLE DB provider or ODBC driver for the data store access, client software for the specific database system used (in the case of SQL databases), a database back-end system accessible to the application (for SQL database systems), and a database. All of these must be accessible to the ADO-based application for it to be fully functional.
The dbGo category of the Tool Palette hosts the dbGo components. These components let you connect to an ADO data store, execute commands, and retrieve data from tables in databases using the ADO framework. The components require the latest version of ADO to be installed on the host computer. Additionally, client software for the target database system (such as Microsoft SQL Server) must be installed, as well as an OLE DB driver or ODBC driver specific to the particular database system.
Most dbGo components have direct counterparts in the components available for other data access mechanisms: a database connection component, TADOConnection, and various types of datasets. In addition, dbGo includes TADOCommand, a simple component that is not a dataset but which represents an SQL command to be executed on the ADO data store.
The main dbGo components are:
| Components | Function |
|---|---|
|
TADOConnection |
A database connection component that establishes a connection with an ADO data store.Multiple ADO dataset and command components can share this connection to execute commands, retrieve data, and operate on metadata. |
|
TRDSConnection |
A database connection component to marshal data in multi-tier database applications that are built using ADO-based application servers. |
|
TADODataSet |
Primary dataset used for retrieving and operating on data.TADODataSet can retrieve data from a single or multiple tables, can connect directly to a data store, or use a TADOConnection component |
|
TADOTable |
A table-type dataset for retrieving and operating on a recordset produced by a single database table.TADOTable can connect directly to a data store or use a TADOConnection component |
|
TADOQuery |
A query-type dataset for retrieving and operating on a recordset produced by a valid SQL statement.TADOQuery can also execute Data Definition Language (DDL) SQL statements. It can connect directly to a data store or use a TADOConnection component. |
|
TADOStoredProc |
A stored procedure-type dataset for executing stored procedures.TADOStoredProc executes stored procedures that may or may not retrieve data. It can connect directly to a data store or use a TADOConnection component. |
|
TADOCommand |
A simple component for executing commands (SQL statements that do not return result sets).TADOCommand can be used with a supporting dataset component, or retrieve a dataset from a table. It can connect directly to a data store or use a TADOConnection component |