sql - 跨越多个日期的酒店价格问题

Question

问题在某种程度上与这个有关，除了我使用参数。我的按钮上有这个：

procedure TForm1.Button1Click(Sender: TObject);
begin
with ABSQuery1 do begin
ABSQuery1.Close;
ABSQuery1.SQL.Clear;
ABSQuery1.SQL.Add('select * from ROOM_RATES where CENIK_ID = :a4 and ROOM_TYPE = :A1');
ABSQuery1.SQL.Add('and rate_Start_DATE < :a3 AND rate_End_DATE  > :a2 ORDER BY rate_Start_DATE ASC ');
ABSQuery1.Params.ParamByName('a1').Value:= cxLookupComboBox2.Text;
ABSQuery1.Params.ParamByName('a2').Value:= cxDateEdit1.Date;
ABSQuery1.Params.ParamByName('a3').Value := cxDateEdit2.Date;
ABSQuery1.Params.ParamByName('a4').Value := cxLookupComboBox1.Text;
ABSQuery1.Open;
end;
end;

这种工作但不是我真正想要的。问题与这个有关： Hotel Booking Rates SQL Problem

问题在于提到的超链接中的重叠日期。现在我得到这个：

如何在上述示例中获得与上述超链接相似的结果？

这是 db 表的快照：

更新（新）：这是按钮上的代码 click ：

procedure TForm1.AdvGlowButton1Click(Sender: TObject);
var
     nxt             : integer;
     mem_from         : TDateTime;
     mem_to           : TDateTime;
     mem_RATE_ID      : integer;
     mem_ROOM_TYPE    : string[10];
     mem_Start_DATE_1 : TDateTime;
     mem_End_DATE_1   : TDateTime;
     mem_RATE_Price_1 : Currency;
     mem_calc_END     : TDateTime;
     mem_calc_DAYS    : integer;
     c_from           : TDateTime;
     c_to             : TDateTime;
     c_from_test      : TDateTime;
     c_to_test        : TDateTime;

begin
ABSQuery2.Close;
ABSQuery2.SQL.Text:='DELETE from TEMP';
ABSQuery2.ExecSQL;
ABSQuery2.SQL.Text:='SELECT * from TEMP ORDER BY ID ';
ABSQuery2.Open;

c_from := cxDateEdit1.Date;
c_to   := cxDateEdit2.Date;

mem_from := cxDateEdit1.Date;
mem_to   := cxDateEdit2.Date;

with ABSQuery1 do begin
ABSQuery1.Close;
ABSQuery1.SQL.Clear;
ABSQuery1.SQL.Add('select * from ROOM_RATES where CENIK_ID = :a4 and ROOM_TYPE = :A1');
ABSQuery1.SQL.Add('and rate_Start_DATE < :a3 AND rate_End_DATE  > :a2 ORDER BY rate_Start_DATE ASC ');
ABSQuery1.Params.ParamByName('a1').Value:= cxLookupComboBox2.Text;
ABSQuery1.Params.ParamByName('a2').Value:= cxDateEdit1.Date;
ABSQuery1.Params.ParamByName('a3').Value := cxDateEdit2.Date;
ABSQuery1.Params.ParamByName('a4').Value := cxLookupComboBox1.Text;
ABSQuery1.Open;

     nxt              := 1;
     mem_RATE_ID      := ABSQuery1.FieldByName('RATE_ID').AsInteger;
     mem_ROOM_TYPE    := ABSQuery1.FieldByName('ROOM_TYPE').AsString ;
     mem_Start_DATE_1 := ABSQuery1.FieldByName('RATE_START_DATE').AsDateTime;
     mem_End_DATE_1   := ABSQuery1.FieldByName('RATE_END_DATE').AsDateTime;
     mem_RATE_Price_1 := ABSQuery1.FieldByName('RATE_PRICE').AsCurrency;

     if mem_to > mem_End_DATE_1 then begin
         mem_calc_END  := mem_End_DATE_1;
         mem_calc_DAYS := Daysbetween(mem_from,mem_End_DATE_1);
     end else begin
         mem_calc_END  := mem_to;
         mem_calc_DAYS := Daysbetween(mem_from,mem_calc_END);
     end;
end;

if ABSQuery1.RecordCount > nxt then ABSQuery1.Next;
with ABSQuery2 do begin
open;
Insert;
  ABSQuery2.FieldByName('RATE_ID').AsInteger:=mem_RATE_ID;
  ABSQuery2.FieldByName('ROOM_TYPE').AsString:=mem_ROOM_TYPE;
  ABSQuery2.FieldByName('DATE_FROM').AsDateTime:=mem_from;
  ABSQuery2.FieldByName('DATE_TO').AsDateTime:= mem_to;//mem_calc_END;
  ABSQuery2.FieldByName('RATE_PRICE').AsCurrency:=mem_RATE_PRICE_1;
  ABSQuery2.FieldByName('DAYS').AsInteger:=mem_calc_DAYS;
  ABSQuery2.FieldByName('TOTAL').AsCurrency:=mem_RATE_PRICE_1 * mem_calc_DAYS;
post;
end;  ///////////////////////////////////////////////////////////////////
if ABSQuery1.RecordCount > nxt then begin
     inc(nxt);

    if mem_to < ABSQuery1.FieldByName('rate_End_DATE').AsDateTime then begin
       mem_calc_END   := mem_to;
       mem_calc_DAYS  := Daysbetween(ABSQuery1.FieldByName('rate_Start_DATE').AsDateTime,mem_calc_END);
    end else begin
       mem_calc_END   := ABSQuery1.FieldByName('rate_End_DATE').AsDateTime;
       mem_calc_DAYS  := Daysbetween(ABSQuery1.FieldByName('rate_Start_DATE').AsDateTime, ABSQuery1.FieldByName('rate_End_DATE').AsDateTime);
    end;
       mem_RATE_ID      := ABSQuery1.FieldByName('RATE_ID').AsInteger;
       mem_ROOM_TYPE    := ABSQuery1.FieldByName('ROOM_TYPE').AsString;
       mem_Start_DATE_1 := ABSQuery1.FieldByName('rate_Start_DATE').AsDateTime;
       mem_End_DATE_1   := ABSQuery1.FieldByName('rate_End_DATE').AsDateTime;
       mem_Rate_Price_1 := ABSQuery1.FieldByName('RATE_PRICE').AsCurrency;

    // calculation : second row.
with ABSQuery2 do begin
Insert;
  FieldByName('RATE_ID').AsInteger:=mem_RATE_ID;
  FieldByName('ROOM_TYPE').AsString:=mem_ROOM_TYPE;
  FieldByName('DATE_FROM').AsDateTime:=mem_Start_DATE_1;
  FieldByName('DATE_TO').AsDateTime:= mem_calc_END;
  FieldByName('RATE_PRICE').AsCurrency:=mem_RATE_PRICE_1;
  FieldByName('DAYS').AsInteger:=mem_calc_DAYS;
  FieldByName('TOTAL').AsCurrency:=mem_RATE_PRICE_1 * mem_calc_DAYS;
post;
end;
 ABSQuery2.refresh;
end;
end;

我得到的结果是这样的：

从数据库快照中可以看出，价格设置正常。

Answer 1