You send SQL statements to a database by including them in Client Library function calls. For example, the following pair of calls executes a DELETE statement:

ret = ct_command(cmd, CS_LANG_CMD,
                  "DELETE FROM Employees
                   WHERE EmployeeID=105"
                 CS_NULLTERM,
                 CS_UNUSED);
ret = ct_send(cmd);

For more information on Open Client functions, see  Open Client 15.0 Client-Library/C Reference Manual.