dbutilseh.pas

最新的 DBGRIDEH4.0

  if S[Pos] = '''' then
  begin
    for i := Pos + 1 to Length(S) do
      if S[i] = '''' then
      begin
        Result := Copy(S, Pos + 1, i - Pos - 1);
        Pos := i + 1;
        Exit;
      end;
    raise Exception.Create(SQuoteIsAbsentEh + S);
  end
  else
  begin
    for i := Pos to Length(S) do
    begin
      if ((S[i] in [' ']) and CheckForOperand(S, SkipBlanks(S, i))) or
        ((S[i] in [')', '('])) or
        (PreferCommaForList and (S[i] = ',')) then
      begin
        Result := Copy(S, Pos, i - Pos);
        Pos := i;
        Exit;
      end;
    end;
    Result := Copy(S, Pos, MAXINT);
    Pos := Length(S) + 1;
  end;
end;

function ReadValues(S: String; var Pos: Integer; PreferCommaForList: Boolean): Variant;
var
  i: Integer;
  vArr: Variant;
begin
  i := 0;
  vArr := VarArrayCreate([0, 0], varVariant);
  while True do
  begin
    vArr[i] := ReadValue(S, Pos, PreferCommaForList);
    if vArr[i] = Null then
      Break;
    if PreferCommaForList and (CharAtPos(S, Pos) = ',') then
      Inc(Pos)
    else
      Break;
    Inc(i);
    VarArrayRedimEh(vArr, i);
  end;
  if i = 0 then
    Result := vArr[0]
  else
    Result := vArr;
end;

function GetLexeme(S: String; var Pos: Integer; var Operator: TSTFilterOperatorEh;
  PreferCommaForList: Boolean): Variant;
var
  Oper: TOperator;
  Operator1: TSTFilterOperatorEh;
  TheWord: String;

  function ReadWord(S: String; Pos: Integer): String;
  var
    c: Char;
    NextPos: Integer;
  begin
    Result := '';
    while True do
    begin
      c := CharAtPos(S, Pos);
      if (c < #32) or (c in [' ','(',')','>','<','=','!','~','&','|','.',',','''','"','+','-']) then
        Exit;
      NextPos := NextCharIndex(S,Pos);
      Result := Result + Copy(S,Pos,NextPos-Pos);
      Pos := NextPos;
    end;
  end;

begin
  Operator := foNon;
  Oper := opNon;
  Result := '';
  if Length(S) < Pos then
    Exit;
  if S[Pos] = '''' then
  begin
    Result := ReadValues(S, Pos, PreferCommaForList);
    Operator := foValue;
  end
  else
  begin
    case S[Pos] of

      '!':
        if CharAtPos(S, Pos + 1) = '=' then
          SetOperatorPos(Pos, 2, Oper, opNotEqual)
        else
          SetOperatorPos(Pos, 1, Oper, opNot);
      '=':
        SetOperatorPos(Pos, 1, Oper, opEqual);
      '(':
        SetOperatorPos(Pos, 1, Oper, opOpenBracket);

      '>':
        if CharAtPos(S, Pos + 1) = '=' then
          SetOperatorPos(Pos, 2, Oper, opGreaterOrEqual)
        else
          SetOperatorPos(Pos, 1, Oper, opGreaterThan);
      '<':
        if CharAtPos(S, Pos + 1) = '=' then
          SetOperatorPos(Pos, 2, Oper, opLessOrEqual)
        else if CharAtPos(S, Pos + 1) = '>' then
          SetOperatorPos(Pos, 2, Oper, opNotEqual)
        else
          SetOperatorPos(Pos, 1, Oper, opLessThan);
      '~':
        SetOperatorPos(Pos, 1, Oper, opLike);
      '&':
        SetOperatorPos(Pos, 1, Oper, opAnd); //And
      '|':
        SetOperatorPos(Pos, 1, Oper, opOr); // Or
    else
      TheWord := ReadWord(S,Pos);
      Oper := GetOperatorByWord(TheWord);
      if Oper <> opNon then
        Inc(Pos, Length(TheWord));
    end; //case

    if Oper = opNon then
    begin
      Result := ReadValues(S, Pos, PreferCommaForList);
      if VarIsNull(Result) then
        Operator := foNon
      else
        Operator := foValue;
      Exit;
    end;

    Pos := SkipBlanks(S, Pos);

    if Oper = opNot then
    begin
      GetLexeme(S, Pos, Operator1, PreferCommaForList);
      case Operator1 of
        foLike: Operator := foNotLike;
        foIn: Operator := foNotIn;
        foNull: Operator := foNotNull;
      end
    end
    else if Oper = opIn then
    begin
      if CharAtPos(S, Pos) = '(' then
        Inc(Pos)
      else
        raise Exception.Create(SLeftBracketExpectedEh + S);
      Operator := foIn;
    end
    else
      Operator := OperatorAdvFilterOperatorMap[Oper];
  end;
end;

function ParseSTFilterExpression(Exp: String; var FExpression: TSTFilterExpressionEh): Boolean;

var
  PreferCommaForList: Boolean;

  procedure ResetPreferCommaForList;
  begin
    if (FExpression.ExpressionType = botNumber) and (DecimalSeparator = ',') then
      PreferCommaForList := False
    else
      PreferCommaForList := True;
  end;

var
  v: Variant;
  op, op1: TSTFilterOperatorEh;
  p: Integer;
begin
  Result := False;

  ResetPreferCommaForList;

  FExpression.Operator1 := foNon;
  FExpression.Operand1 := Null;
  FExpression.Relation := foNon;
  FExpression.Operator2 := foNon;
  FExpression.Operand2 := Null;

  Exp := Trim(Exp);
  if Exp = '' then
    Exit;
  // 1 [Oper] + Values
  p := SkipBlanks(Exp, 1);
  v := GetLexeme(Exp, p, op, PreferCommaForList);
  if op = foValue then
  begin
    if VarIsArray(v) then
      FExpression.Operator1 := foIn
    else if FExpression.ExpressionType = botString then
      FExpression.Operator1 := foLike
    else
      FExpression.Operator1 := foEqual;
    FExpression.Operand1 := v;
  end
  else if (op = foNon) and (Length(Exp) <> 0) then
    raise Exception.Create(SErrorInExpressionEh + Exp)
  else
  begin
    if op in [foIn, foNotIn] then
      PreferCommaForList := True;
    p := SkipBlanks(Exp, p);
    v := GetLexeme(Exp, p, op1, PreferCommaForList);
    FExpression.Operator1 := op;
    if op1 = foNull then
      if op = foEqual then
        FExpression.Operator1 := foNull
      else if op = foNotEqual then
        FExpression.Operator1 := foNotNull
      else
        raise Exception.Create(SUnexpectedExpressionBeforeNullEh + Exp)
    else if op1 <> foValue then
      raise Exception.Create(SUnexpectedExpressionAfterOperatorEh + Exp);
    FExpression.Operand1 := v;
    if op in [foIn, foNotIn] then
    begin
      p := SkipBlanks(Exp, p);
      if CharAtPos(Exp, p) = ')' then
        Inc(p)
      else
        raise Exception.Create(SRightBracketExpectedEh + Exp);
      ResetPreferCommaForList;
    end;
  end;

  while True do
  begin
    // 2 And or Or
    p := SkipBlanks(Exp, p);
    v := GetLexeme(Exp, p, op, PreferCommaForList);
    if op = foNon then
      if p <> Length(Exp) + 1 then
        raise Exception.Create(SIncorrectExpressionEh + Exp)
      else
        Break;
    if not (op in [foAND, foOR]) then
      raise Exception.Create(SUnexpectedANDorOREh + Exp);
    FExpression.Relation := op;

    // 3 [Oper] + Values
    p := SkipBlanks(Exp, p);
    v := GetLexeme(Exp, p, op, PreferCommaForList);
    if op = foNon then
      if p <> Length(Exp) + 1 then
        raise Exception.Create(SIncorrectExpressionEh + Exp)
      else
        Break;
    if op = foValue then
    begin
      if VarIsArray(v) then
        FExpression.Operator2 := foIn
      else if FExpression.ExpressionType = botString then
        FExpression.Operator2 := foLike
      else
        FExpression.Operator2 := foEqual;
      FExpression.Operand2 := v;
    end
    else if (op = foNon) and (Length(Exp) <> 0) then
      raise Exception.Create(SErrorInExpressionEh + Exp)
    else
    begin
      if op in [foIn, foNotIn] then
        PreferCommaForList := True;
      p := SkipBlanks(Exp, p);
      v := GetLexeme(Exp, p, op1, PreferCommaForList);
      FExpression.Operator2 := op;
      if op1 = foNull then
        if op = foEqual then
          FExpression.Operator2 := foNull
        else if op = foNotEqual then
          FExpression.Operator2 := foNotNull
        else
          raise Exception.Create(SUnexpectedExpressionBeforeNullEh + Exp)
      else if op1 <> foValue then
        raise Exception.Create(SUnexpectedExpressionAfterOperatorEh + Exp);
      FExpression.Operand2 := v;
      ResetPreferCommaForList;
    end;
    Result := True;
    Break;
  end;

  if FExpression.Operator1 in [foEqual..foNotIn] then
    ConvertVarStrValues(FExpression.Operand1, FExpression.ExpressionType)
  else
    FExpression.Operand1 := Null;

  if FExpression.Operator2 in [foEqual..foNotIn] then
    ConvertVarStrValues(FExpression.Operand2, FExpression.ExpressionType)
  else
    FExpression.Operand2 := Null;
end;

function ParseSTFilterExpressionEh(Exp: String; var FExpression: TSTFilterExpressionEh): Boolean;

var
  PreferCommaForList: Boolean;

  procedure ResetPreferCommaForList;
  begin
    if (FExpression.ExpressionType = botNumber) and (DecimalSeparator = ',') then
      PreferCommaForList := False
    else
      PreferCommaForList := True;
  end;

var
  v: Variant;
  op, op1: TSTFilterOperatorEh;
  p: Integer;
begin
  Result := False;

  ResetPreferCommaForList;

  FExpression.Operator1 := foNon;
  FExpression.Operand1 := Null;
  FExpression.Relation := foNon;
  FExpression.Operator2 := foNon;
  FExpression.Operand2 := Null;

  Exp := Trim(Exp);
  if Exp = '' then
    Exit;
  // 1 [Oper] + Values
  p := SkipBlanks(Exp, 1);
  v := GetLexeme(Exp, p, op, PreferCommaForList);
  if op = foValue then
  begin
    if VarIsArray(v) then
      FExpression.Operator1 := foIn
    else if FExpression.ExpressionType = botString then
      FExpression.Operator1 := foLike
    else
      FExpression.Operator1 := foEqual;
    FExpression.Operand1 := v;
  end
  else if (op = foNon) and (Length(Exp) <> 0) then
    raise Exception.Create(SErrorInExpressionEh + Exp)
  else
  begin
    if op in [foIn, foNotIn] then
      PreferCommaForList := True;
    p := SkipBlanks(Exp, p);
    v := GetLexeme(Exp, p, op1, PreferCommaForList);
    FExpression.Operator1 := op;
    if op1 = foNull then
      if op = foEqual then
        FExpression.Operator1 := foNull
      else if op = foNotEqual then
        FExpression.Operator1 := foNotNull
      else
        raise Exception.Create(SUnexpectedExpressionBeforeNullEh + Exp)
    else if op1 <> foValue then
      raise Exception.Create(SUnexpectedExpressionAfterOperatorEh + Exp);
    FExpression.Operand1 := v;
    if op in [foIn, foNotIn] then
    begin
      p := SkipBlanks(Exp, p);
      if CharAtPos(Exp, p) = ')' then
        Inc(p)
      else
        raise Exception.Create(SRightBracketExpectedEh + Exp);
      ResetPreferCommaForList;
    end;
  end;

  while True do
  begin
    // 2 And or Or
    p := SkipBlanks(Exp, p);
    v := GetLexeme(Exp, p, op, PreferCommaForList);
    if op = foNon then
      if p <> Length(Exp) + 1 then
        raise Exception.Create(SIncorrectExpressionEh + Exp)
      else
        Break;
    if not (op in [foAND, foOR]) then
      raise Exception.Create(SUnexpectedANDorOREh + Exp);
    FExpression.Relation := op;

    // 3 [Oper] + Values
    p := SkipBlanks(Exp, p);
    v := GetLexeme(Exp, p, op, PreferCommaForList);
    if op = foNon then
      if p <> Length(Exp) + 1 then
        raise Exception.Create(SIncorrectExpressionEh + Exp)
      else
        Break;
    if op = foValue then
    begin