main.pas

简单查询软件 批量查询 研究生编程 查找水文数据

unit main;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Grids, DBGrids, DB, DBTables, StdCtrls, Mask, DBCtrls;

type
  TForm1 = class(TForm)
    yearlb: TLabel;
    stationcb: TComboBox;
    stationlb: TLabel;
    monthlb: TLabel;
    yearcb: TComboBox;
    monthcb: TComboBox;
    Button1: TButton;
    Button2: TButton;
    Query1: TQuery;
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    searchQuery: TQuery;
    DataSource2: TDataSource;
    DBGrid2: TDBGrid;
    differenceQuery: TQuery;
    differenceDataSource: TDataSource;
    differenceDBGrid: TDBGrid;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation


{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
  SqlStr : String;
begin
  SqlStr:= ' SELECT  AVG(rainfall) as 降雨量平均值,AVG(temperature) as 温度平均值 ';
  SqlStr:=SqlStr+' FROM CYQ ';
  SqlStr:=SqlStr+' WHERE ';
  if (stationcb.Text<>'') then
  SqlStr:=SqlStr+' Station='+''''+stationcb.Text+'''' ;
  if (yearcb.Text<>'') then
  SqlStr:=SqlStr+' AND CYQYear='+''''+yearcb.Text+'''';
  if (monthcb.Text<>'') then
  SqlStr:=SqlStr+' AND CYQMonth='+''''+monthcb.Text+'''';


  searchQuery.Close;
  searchQuery.SQL.Clear;
  searchQuery.SQL.Add(SqlStr);
  searchQuery.Prepare;
  searchQuery.Open;
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  SqlStr : String;
begin
  //SqlStr:= ' select  CYQ.rainfall-CYQ002.avg1 as 各月降雨量差值, CYQ.temperature-CYQ002.avg2 as 各月温度差值 ';
  SqlStr:= 'select  Station,CYQ.CYQYear,CYQ.CYQMonth, CYQ.rainfall-CYQ002.avg1 as 各月降雨量差值, CYQ.temperature-CYQ002.avg2 as 各月温度差值 ';
  SqlStr:=SqlStr+' FROM CYQ,';
  SqlStr:=SqlStr+ ' (SELECT  AVG(rainfall) as avg1,AVG(temperature) as avg2 ';
  SqlStr:=SqlStr+' FROM CYQ ';
  SqlStr:=SqlStr+' WHERE ';
  if (stationcb.Text<>'') then
  SqlStr:=SqlStr+' Station='+''''+stationcb.Text+'''' ;
  if (yearcb.Text<>'') then
  SqlStr:=SqlStr+' AND CYQYear='+''''+yearcb.Text+'''';
  if (monthcb.Text<>'') then
  SqlStr:=SqlStr+' AND CYQMonth='+''''+monthcb.Text+'''';

  SqlStr:=SqlStr+' ) as CYQ002 ';

  SqlStr:=SqlStr+' WHERE ';
  if (stationcb.Text<>'') then
  SqlStr:=SqlStr+' Station='+''''+stationcb.Text+'''' ;
  if (yearcb.Text<>'') then
  SqlStr:=SqlStr+' AND CYQYear='+''''+yearcb.Text+'''';
  if (monthcb.Text<>'') then
  SqlStr:=SqlStr+' AND CYQMonth='+''''+monthcb.Text+'''';

  differenceQuery.Close;
  differenceQuery.SQL.Clear;
  differenceQuery.SQL.Add(SqlStr);
  differenceQuery.Prepare;
  differenceQuery.Open;
end;

end.