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;