In Client-Library, CS_COMMAND is the control structure for sending commands to a server and processing results. Multiple command structures may be allocated from a single connection structure.
DB-Library applications can send the following types of commands:
Language commands – define a batch of one or more SQL statements and send it to the server to be compiled and executed. See “Sending language commands”.
Remote procedure call (RPC) commands – invoke an Adaptive Server Enterprise stored procedure or Open Server registered procedure, passing parameters in their declared datatypes. See “Sending RPC commands”.
TDS passthrough calls – used by Open Server gateways, read and write raw TDS packets. See “TDS passthrough”.
There are other Client-Library command types that have no DB-Library equivalents. Chapter 5, “Choosing Command Types,” in the Open Client Client-Library/C Programmers Guide summarizes the Client-Library command types.