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DBdefine
Synopsis
Define user buffers for data returned by the select query.
Input Ports
ptr dbvisual_connect_descriptor - connection to database engine
ptr dbquery_descriptor - executed query handle with select list description
int process_statement - trigger to invoke the method
Parameters
Output Ports
ptr dbvisual_connect_descriptor - connection to database engine
ptr dbquery_descriptor - executed query handle with pointer to user buffers
int done - finished processing? Can be used as a trigger to downstream modules
Description
DBdefine receives the select list description and allocates user buffers to retrieve one row of data according to the type information received.
Validation of connection and statement handle is the first task. If valid, the module queries the statement handle for parameters describing each select list item for their name and internal type. For each parameter, appropriate sized user buffers are allocated for retrieval. If either the connection handle or the statement handle is NULL and process_statement is set, this module will display an error message. If the statement handle has not been "executed", an appropriate error message will be displayed.
Example
File
See also related modules
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