DBexecuteStatement

Synopsis

Executes the prepared SQL statement

Input Ports

ptr dbvisual_connect_descriptor – connection to database engine

ptr dbquery_descriptor – prepared query handle

int process_statement – trigger to invoke the method

Output Ports

ptr dbvisual_connect_descriptor – connection to database engine

ptr dbquery_descriptor – executed query handle with select list description

int done – finished processing? Can be used as a trigger to downstream modules

Description

This group will send the query to server for execution. Upon returning, information regarding select list items will be available. No prefetching is done because we don’t know the select list item types because execution. Thus, no user buffer can be appropriately defined before hand, which is a requirement for prefetching.

When invoked, the DBexecuteStatement group will first verify that a valid connection is available and a valid statement handle exists. It then passes the statement handle to the server for execution once process_statement is set to 1.

Upon successful execution, a statement handle with the description of select list items will be passed downstream. Otherwise, NULL is assigned. Attribute done will be set to 1 to indicate end of processing only when executed successfully.

See Also

DBprepareStatement, DBdefine