VB Prodigy Tutorial (cont.)--vb ADO Object

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Introduction to ADO

Resources:

Introduction to ADO: Http://bianceng.cn/VBjc/sjcz/sj2.htm

ADO Object Model: http://bianceng.cn/Programming/VB_NET/200705/1201.htm

ADO is another API for developing access to OLE DB data source applications. There are a variety of programming languages that support ADO, such as vb,vc++,vj++. ADO provides a more advanced and understandable mechanism for accessing OLE DB data sources, combining the advantages of DAO and RDO. and provides a portal for OLE DB data sources. OLE DB is a database architecture that provides a common data synthesis capability for corporate networks (from mainframe to desktop data, regardless of the specific type of data), and OLE DB is more universal and efficient in data channels than ODBC. This is because it allows for more data types to be contacted based on COM and because ADO is designed specifically for developing client/server programs. The following illustration is the structure of a typical ADO application.

The characteristics of ADO are as follows:

▲ supports batch updates. That is, buffering the updated records and transferring them to the server synchronously.

▲ supports all types of cursors. Includes only forward type, critical value type and dynamic and static type.

▲ supports server-side stored procedures. These processes can greatly improve the versatility of your application.

▲ supports queries that return more than one recordset.

▲ Support the purpose of the query. This includes restricting the number of records returned, activating the filtering and pre statement of the returned records.

ADO is made up of the following objects: Command,connect,error,field,parameter and recordsets. The following figure shows the hierarchical structure of the ADO object. All ADO objects except the error and field can be created individually, while the Command,error and parameter objects are optional.