sql= insert | select | update  .
  value_litteral= VALUE_LITTERAL | NAME .
  integer_litteral= INTEGER .

  table_or_view_name= NAME .
  name_view_procedure= NAME .

  column_name= NAME .
  collation_name= NAME .
  alias_name= NAME .

  select= F .
  select_expression= select .

  insert= INSERT INTO table_or_view_name
        [ '(' column_name { ',' column_name } ')' ]
        ( VALUES '(' value_litteral { ',' value_litteral } ')' | select_expression ) .

  functions= average | count | max | min | sum | upper .
    average= AVG '(' [ ALL | DISTINCT ] value_litteral ')' .
    count= COUNT '(' '*' | [ ALL | DISTINCT ] value_litteral ')' .
    max= MAX '(' [ ALL | DISTINCT ] value_litteral ')' .
    min= MIN '(' [ ALL | DISTINCT ] value_litteral ')' .
    sum= SUM '(' [ ALL | DISTINCT ] value_litteral ')' .
    upper= UPPER '(' value_litteral ')' .

  search_condition= search_value { ( OR | AND ) search_condition } .
    search_value=
          value_litteral
            ( [ NOT ] ( between | like | in | compare | containing | starting )
              | IS [ NOT ] NULL )
        | ( ALL | SOME | ANY ) '(' select_column_list ')'
        | EXISTS '(' select_expression ')'
        | SINGULAR '(' select_expression ')'
        | '(' search_condition ')'
        | NOT search_condition .
      select_one_column= select .
      select_column_list= select .

      between= BETWEEN value_litteral AND value_litteral .
      like= LIKE value_litteral [ ESCAPE value_litteral ].
      in= IN '(' value_litteral { ',' value_litteral } | select_column_list ')' .
      compare= operator ( value_litteral | '(' select_one_column ')' ) .
        operator= '=' | '<' | '>' | '<=' | '>=' | '<>' .
      containing= CONTAINING value_litteral .
      starting= STARTING [ WITH ] value_litteral .

  select= SELECT [ DISTINCT | ALL ]
      ( '*' | functions | value_litteral { ',' value_litteral } )
      FROM from_table_reference { ',' from_table_reference }
      [ WHERE search_condition ]
      [ GROUP BY column_name
        [ COLLATE collation_name ] { ',' column_name [ COLLATE collation_name ] } ]
      [ HAVING search_condition ]
      [ UNION select_expression [ ALL ] ]
      [ ORDER BY order_list ] .
    // -- DUPS: NAME, co-recursive
    from_table_reference= NAME procedure_end | joined_table .
      procedure_end= [ '(' value_litteral { ',' value_litteral } ')' ] [ alias_name ] .
      joined_table= ( name_view_procedure join_on | '(' joined_table ')' ) { join_on } .
        join_on= join_type ( joined_table | name_view_procedure ) ON search_condition .
          join_type= ( [ INNER | { LEFT | RIGHT | FULL } [OUTER] ] ) JOIN .

    order_list= ( column_name | integer_litteral ) [ COLLATE collation_name ]
        [ ascending_or_descending ] { ',' order_list } .
      ascending_or_descending= ASC | ASCENDING | DESC | DESCENDING .

  update= UPDATE table_or_view_name
        SET column_name '=' value_litteral
        { ',' column_name '=' value_litteral }
        [ WHERE search_condition ] .

                         e_start_punctuation,
                           e_multiply_symbol, // *
                           e_semi_colon_symbol, // ;
                           // ...
                           e_different_symbol, // <>
                         e_end_punctuation,

                         e_identifier_start,
                           e_SELECT_symbol,
                           e_INSERT_symbol,
                           // ...
                           e_UPPER_symbol,
                         e_identifier_symbol,

                         e_end_of_parse_symbol
                     );

      t_sql_symbol_type_set= set of t_sql_symbol_type;

const k_sql_litteral_symbol_set= [e_integer_litteral_symbol,
          e_double_litteral_symbol, e_string_litteral_symbol];
      k_sql_litteral_and_identifier_symbol_set= k_sql_litteral_symbol_set
          + [e_identifier_symbol, e_colon_symbol];

function f_sql_symbol_type_name(p_sql_symbol_type: t_sql_symbol_type): String;
function f_sql_symbol_type_set_name(
    p_sql_symbol_type_set: t_sql_symbol_type_set): String;
function f_sql_identifier_type(p_symbol_string: String): t_sql_symbol_type;

                  m_display_symbol_read: Boolean;

                  constructor create_sql_scanner(p_name, p_file_name: String);
                  function f_initialized: Boolean;
                  function f_read_symbol: Boolean;
                  procedure test_sql_scanner;
                end; // c_sql_scanner

  // ...

  begin // f_read_symbol
    m_symbol_string:= '';
    m_sql_symbol_type:= e_unknown_symbol;

    if f_end_of_text
      then begin
          Result:= False;
          m_sql_symbol_type:= e_end_of_parse_symbol;
        end
      else begin
          get_blanks;

          if m_buffer_index< m_buffer_size
            then begin
                case m_pt_buffer[m_buffer_index] of
                  'a'..'z', 'A'..'Z' : get_identifier;
                  '-', '0'..'9' : get_number;
                  '''' : get_string_litteral;

                  '*' : get_one_operator(e_multiply_symbol);
                  ':' : get_one_operator(e_colon_symbol);
                  '.' : get_one_operator(e_point_symbol);
                  ';' : get_one_operator(e_semi_colon_symbol);
                  ',' : get_one_operator(e_comma_symbol);
                  '=' : get_one_operator(e_equal_symbol);

                  '<' : if (m_buffer_index+ 1< m_buffer_size)
                            and (m_pt_buffer[m_buffer_index+ 1]= '=')
                          then get_two_operator(e_lower_or_equal_symbol)
                          else
                            if (m_buffer_index+ 1< m_buffer_size)
                                and (m_pt_buffer[m_buffer_index+ 1]= '>')
                              then get_two_operator(e_different_symbol)
                              else  get_one_operator(e_lower_symbol);
                  '>' : if (m_buffer_index+ 1< m_buffer_size)
                            and (m_pt_buffer[m_buffer_index+ 1]= '=')
                          then get_two_operator(e_greater_or_equal_symbol)
                          else get_one_operator(e_greater_symbol);

                  '(' : get_one_operator(e_opening_parenthesis_symbol);
                  ')' : get_one_operator(e_closing_parenthesis_symbol);
                  else
                    display_bug_stop('unknown_char_in_sql '+ m_pt_buffer[m_buffer_index]
                        + '< '+ IntToStr(Ord(m_pt_buffer[m_buffer_index])));
                end; // case
              end
            else m_sql_symbol_type:= e_end_of_parse_symbol;

          Result:= True;
        end; // not eof
  end; // f_read_symbol

                 constructor create_sql_parser(p_name: String);

                   procedure display_error(p_text: string);
                   procedure start_parsing;
                   function f_symbol_type: t_sql_symbol_type;
                   function f_symbol_string: String;
                   procedure read_symbol;
                   procedure check(p_sql_symbol_type: t_sql_symbol_type);
                   procedure check_set(p_sql_symbol_type_set: t_sql_symbol_type_set);
                 procedure parse_sql;
               end; // c_sql_parser

    parse_table_or_view_name;

    IF f_symbol_type= e_opening_parenthesis_symbol
      THEN BEGIN
          read_symbol;
          parse_column_name;
          WHILE f_symbol_type= e_comma_symbol DO
          BEGIN
            read_symbol;
            parse_column_name;
          END; // WHILE {
          check(e_closing_parenthesis_symbol);
          read_symbol;
        END; // IF [

    IF f_symbol_type= e_VALUES_symbol
      THEN BEGIN
          read_symbol;
          check(e_opening_parenthesis_symbol);
          read_symbol;
          parse_value_litteral;
          WHILE f_symbol_type= e_comma_symbol DO
          BEGIN
            read_symbol;
            parse_value_litteral;
          END; // WHILE {
          check(e_closing_parenthesis_symbol);
          read_symbol;
        END 
      ELSE 
        IF f_symbol_type= e_SELECT_symbol
          THEN
            parse_select_expression 
          ELSE display_error('VALUES, SELECT');
  END; // parse_insert

 
SELECT *
  FROM parts
  WHERE (parts.OnOrder > parts.OnHand)