$sql="SELECT distinct class_teacher.cs_code,course.t_name FROM class_teacher,course WHERE class_teacher.cs_code=course.cs_code AND course.fac_id='A' AND class_teacher.sm='$sm' AND class_teacher.yr='$yr' ORDER BY course.t_name";
ERROR:
Warning: odbc_exec(): SQL error: [Microsoft][ODBC driver for Oracle]Cannot use Keyset-driven cursor on join, with distinct clause, union, intersect or minus or on read only result set, SQL state S1C00 in SQLExecDirect in c:\appserv\www\work\grade\main_subject.php