15.5. Using UpdateGrams to Modify Data

Updategrams allow database updates to be defined as XML. This is ultimately achieved by mapping the XML nodes against corresponding database columns. Updategrams can be used to replace existing data access components in a middle tier. A typical application will include a middle tier consisting of business logic and data access code. The data access code will interact with the database using disconnected recordsets and command objects calling stored procedures. Most of the data access section of the middle tier can be replaced with updategrams.

Most data access tiers (both middle tier code and stored procedures) will deal individually with specific database tables or groups of related tables. This can inhibit performance and often several round trips to the database are required to complete a transaction. Updategrams solve this problem by including all the data in an XML document that is then mapped to database tables and columns. The entire database update can then be accomplished at once. This update can include inserting, updating and deleting data.

The xmlsql_update() function supports XML-based insert, update, and delete operations performed on an existing table in the database. xmlsql_update()