losestorequery.pas

物流管理系统是一个典型的数据库应用程序

unit losestorequery;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, instorequery, DB, Grids, DBGrids, ComCtrls, StdCtrls, Buttons,
  ExtCtrls;

type
  Tf_losestorequery = class(Tf_instorequery)
    procedure storagefieldChange(Sender: TObject);override;//改写父类中的方法
    procedure QueryClick(Sender: TObject); override; //改写父类中的方法
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  f_losestorequery: Tf_losestorequery;

implementation
  uses data;
{$R *.dfm}
//当查询条件改变时,相应的值也会发生改变
procedure Tf_losestorequery.storagefieldChange(Sender: TObject);
begin
  StorageValue.Clear;  //清空组合框中的数据
  Case StorageField.ItemIndex of  //根据组合框中不同的状态索引查询不同的数据
    0:
    begin
      With t_data.Query1 do
      begin
        Close;
        SQL.Clear;
        SQL.Add('select storename from tb_storeinfo');
        Open;
      end;
      if t_data.Query1.RecordCount>0 then
      begin
        while not t_data.Query1.Eof do
        begin
          StorageValue.Items.Add(Trim(t_data.Query1.Fields[0].Value));
          t_data.Query1.Next;
        end;
      end;
    end;
    1,2:
    begin
      With t_data.Query1 do
      begin
        Close;
        SQL.Clear;
        SQL.Add('select workername from tb_employeeinfo');
        Open;
      end;
      if t_data.Query1.RecordCount>0 then
      begin
        while not t_data.Query1.Eof do
        begin
          StorageValue.Items.Add(Trim(t_data.Query1.Fields[0].Value));
          t_data.Query1.Next;
        end;
      end;
    end;
  end;
end;
//处理查询按钮的单击事件,程序中进行了多种条件判断
procedure Tf_losestorequery.QueryClick(Sender: TObject);
begin
  if (Storagecon.Checked = True) or( Date.Checked = True) then //检查是否设置了查询条件
  begin
    if (Storagecon.Checked = True )and (Date.Checked = False)then //不进行时间段查询
    begin
      if(Trim(StorageField.Text)<>'')and(Trim(StorageValue.Text)<>'') then //判断是否设置了查询条件
      begin
        With t_data.Query2 do
        begin
          Close;
          SQL.Clear;
          SQL.Add('select * from v_losestorequery where ');
          case Storagefield.ItemIndex of
            0: SQL.Add('storename = :Value');
            1: SQL.Add('principal = :Value');
            2: SQL.Add('operator  = :Value');
            3: SQL.Add('loseid = :Value');
          end;
          Parameters.ParamByName('Value').Value := Trim(Storagevalue.Text);
          Open;
        end;
        if t_data.Query2.RecordCount>0 then //是否有数据返回 ,如果有则汇总物资数量
        begin
          With t_data.Query3 do
          begin
            Close;
            SQL.Clear;
            SQL.Add('Select sum(num) as storesum , storename from  v_losestorequery where ');
            case Storagefield.ItemIndex of
            0: SQL.Add('storename = :Value');
            1: SQL.Add('principal = :Value');
            2: SQL.Add('operator  = :Value');
            3: SQL.Add('loseid = :Value');
            end;
            SQL.Add('  Group by storename');
            Parameters.ParamByName('Value').Value := Trim(Storagevalue.Text);
            Open;
          end;
          Source1.DataSet := t_data.Query2;
          Source2.DataSet := t_data.Query3;
        end
        else
        begin
          Application.MessageBox('没有找到符合条件的记录.','提示',64);
          Source1.DataSet := Nil;
          Source2.DataSet := Nil;
        end;
      end;
    end
    else if (Storagecon.Checked = False )and (Date.Checked = True)then  //只按时间段查询
    begin
      With t_data.Query2 do
      begin
        Close;
        SQL.Clear;
        SQL.Add('select * from v_losestorequery where');
        SQL.Add(' TimeDate >= :FromDate and Timedate < :ToDate');
        Parameters.ParamByName('FromDate').Value := Trunc(FromDate.DateTime);
        Parameters.ParamByName('ToDate').Value := Trunc(ToDate.DateTime)+1;
        Open;
      end;
      if t_data.Query2.RecordCount>0 then  //如果有数据返回则汇总物资数量
      begin
        With t_data.Query3 do
        begin
          Close;
          SQL.Clear;
          SQL.Add('Select sum(num) as storesum ,storename from v_losestorequery where ');
          SQL.Add(' TimeDate >= :FromDate and Timedate < :ToDate');
          SQL.Add(' Group by storename');
          Parameters.ParamByName('FromDate').Value := Trunc(FromDate.DateTime);
          Parameters.ParamByName('ToDate').Value := Trunc(ToDate.DateTime)+1;
          Open;
        end;
        Source1.DataSet := t_data.Query2;
        Source2.DataSet := t_data.Query3;
      end
      else
      begin
        Application.MessageBox('没有找到符合条件的记录.','提示',64);
        Source1.DataSet := Nil;
        Source2.DataSet := Nil;
      end;
    end
    else  //即按字段查询又按时间段查询
    begin
      if(Trim(StorageField.Text)<>'')and(Trim(StorageValue.Text)<>'') then //是否设置了查询条件
      begin
        With t_data.Query2 do
        begin
          Close;
          SQL.Clear;
          SQL.Add('select * from v_losestorequery where ');
          case Storagefield.ItemIndex of
            0: SQL.Add('storename = :Value');
            1: SQL.Add('principal = :Value');
            2: SQL.Add('operator  = :Value');
            3: SQL.Add('loseid = :Value');
          end;
          SQL.Add(' and TimeDate >= :FromDate and Timedate < :ToDate');
          Parameters.ParamByName('FromDate').Value := Trunc(Fromdate.DateTime);
          Parameters.ParamByName('ToDate').Value := Trunc(ToDate.DateTime)+1;
          Parameters.ParamByName('Value').Size := 100;
          Parameters.ParamByName('Value').Value := Trim(Storagevalue.Text);
          Open;
        end;
        if t_data.Query2.RecordCount>0 then //是否有结果集返回,如果有则汇总物资数量
        begin
          With t_data.Query3 do
          begin
            Close;
            SQL.Clear;
            SQL.Add('Select sum(num) as storesum ,storename from  v_losestorequery where ');
            case Storagefield.ItemIndex of
              0: SQL.Add('storename = :Value');
              1: SQL.Add('principal = :Value');
              2: SQL.Add('operator  = :Value');
              3: SQL.Add('loseid = :Value');
            end;
            SQL.Add(' and TimeDate >= :FromDate and Timedate < :ToDate ');
            SQL.Add(' Group by storename');
            Parameters.ParamByName('Value').Size := 100;
            Parameters.ParamByName('Value').Value := Trim(Storagevalue.Text);
            Parameters.ParamByName('FromDate').Value := Trunc(FromDate.DateTime);
            Parameters.ParamByName('ToDate').Value := Trunc(ToDate.DateTime)+1;
            Open;
          end;
          Source1.DataSet := t_data.Query2;
          Source2.DataSet := t_data.Query3;
        end
        else
        begin
          Application.MessageBox('没有找到符合条件的记录.','提示',64);
          Source1.DataSet := Nil;
          Source2.DataSet := Nil;
        end;
      end;
    end;
  end
  else
    Application.MessageBox('请设置查询条件.','提示',64);
end;

end.