To update a text or image column, a client application typically calls the ct_command routine to initiate a send-data command. The client then calls the ct_data_info command to retrieve CS_IODESC and determine the appropriate SQL command to generate (update or writetext) in a subsequent call to the ct_send_data routine. One or more additional calls to ct_send_data follow for the purpose of sending the text or image data. The client concludes with calls to the ct_send and ct_results routines. A language event occurs at the server, which processes the SQL command. A bulk event follows, causing the server to read the specified amount of text or image data.
To simplify this process and potentially improve performance, a client can suppress the generation of the SQL command (update or writetext) and send data directly to the server bulk handler. The client must initiate the send-data command by calling the ct_command routine with the type parameter set to CS_SEND_DATA_NOCMD. The client application can then use send-data commands to send only text or image data to the server bulk handler. When a bulk event occurs at the server, a 4-byte field is sent indicating the total number of bytes to be sent, followed by the text or image data. The bulk handler reads the total number of bytes expected using srv_text_info and the data using srv_get_data.
