oracle instr,substr 截取字符串

                declare
                
  lv_str 
                varchar(500);
begin
  lv_str :=‘abcd$xxx‘;
  dbms_output.put_line(instr(lv_str, ‘$‘));
  dbms_output.put_line(substr(lv_str, 0, instr(lv_str, ‘$‘) -1));
  dbms_output.put_line(substr(lv_str, instr(lv_str, ‘$‘) +1));
end;