DBfetch

Synopsis

Retrieve data returned by SQL query into allocated user buffers.

Input Ports

ptr dbvisual_connect_descriptor – connection to database engine

ptr dbquery_descriptor – defined query handle with reference to allocated user buffers

int process_statement – trigger to invoke the method

Output Ports

ptr dbvisual_connect_descriptor – connection to database engine

SDI_Column columns – 2D arrays of data returned

SDI_Column null_indicators – 2D arrays of null indicators

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

Description

DBfetch uses the user buffers allocated during the define stage to issue fetch commands against the appropriate database server. Data will then be copied from temporary buffers to columns and null_indicators array. Space for these arrays are expanded once the existing buffer is filled in multiple of initial user buffer size.

The connection and statement handle is first verified. 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 defined, an appropriate error message will be displayed.