unit1.pas

非常丰富的delphi小程序,相信会对你有帮助

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    DataSource1: TDataSource;
    DBGrid1: TDBGrid;
    Query1: TQuery;
    BitBtn2: TBitBtn;
    BitBtn3: TBitBtn;
    BitBtn4: TBitBtn;
    Label1: TLabel;
    BitBtn1: TBitBtn;
    BitBtn5: TBitBtn;
    GroupBox1: TGroupBox;
    DateTimePicker1: TDateTimePicker;
    DateTimePicker2: TDateTimePicker;
    Label2: TLabel;
    Label3: TLabel;
    BitBtn6: TBitBtn;
    BitBtn7: TBitBtn;
    BitBtn8: TBitBtn;
    BitBtn9: TBitBtn;
    BitBtn10: TBitBtn;
    Label4: TLabel;
    procedure BitBtn2Click(Sender: TObject);
    procedure BitBtn3Click(Sender: TObject);
    procedure BitBtn4Click(Sender: TObject);
    procedure BitBtn1Click(Sender: TObject);
    procedure BitBtn5Click(Sender: TObject);
    procedure BitBtn6Click(Sender: TObject);
    procedure BitBtn7Click(Sender: TObject);
    procedure BitBtn8Click(Sender: TObject);
    procedure BitBtn9Click(Sender: TObject);
    procedure BitBtn10Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.BitBtn2Click(Sender: TObject);
begin
Query1.Close;
Query1.SQL.Clear;
Query1.SQL.Add('Select 姓名, 工资*0.8 AS 实发工资 from employee');
Query1.Open;
Label1.Caption:='操作提示：查询姓名和工资两列数据，其中“工资”列的标题更改为“实发工资”';
end;

procedure TForm1.BitBtn3Click(Sender: TObject);
begin
Query1.Close;
Query1.SQL.Clear;
Query1.SQL.Add('Select *  from  employee where 学历="硕士研究生" and 性别="男"');
Query1.Open;
Label1.Caption:='操作提示：查询所有学历为“硕士研究生”的“男”雇员';
end;

procedure TForm1.BitBtn4Click(Sender: TObject);
begin
Query1.Close;
Query1.SQL.Clear;
Query1.SQL.Add('Select *  from  employee where 姓名 like "王%"');
Query1.Open;
Label1.Caption:='操作提示：查询所有姓氏为“王”的雇员';
end;

procedure TForm1.BitBtn1Click(Sender: TObject);
begin
Query1.Close;
Query1.SQL.Clear;
Query1.SQL.Add('Select * from employee');
Query1.Open;
Label1.Caption:='操作提示：从employee数据表查询各个记录的所有列数据';
end;

procedure TForm1.BitBtn5Click(Sender: TObject);
begin
Query1.Close;
Query1.SQL.Clear;
Query1.SQL.Add('Select *  from  employee where 生日>=:VarDate1 and  生日<:VarDate2');
Query1.ParamByName('VarDate1').AsDate:= DateTimePicker1.Date;
Query1.ParamByName('VarDate2').AsDate:= DateTimePicker2.Date;
Query1.Open;
Label1.Caption:='操作提示：使用生日的日期范围参数来查询符合条件的雇员';
end;

procedure TForm1.BitBtn6Click(Sender: TObject);
begin
Query1.Close;
Query1.SQL.Clear;
Query1.SQL.Add('Select employee.姓名,department.上班制度 from  employee,department where employee.所在部门=department.部门编号');
Query1.Open;
Label1.Caption:='操作提示：姓名和上班制度两列数据分别来自employee、department数据表，它们是通过部门编号进行关联的';
end;

procedure TForm1.BitBtn7Click(Sender: TObject);
begin
Query1.Close;
Query1.SQL.Clear;
Query1.SQL.Add('Select 所在部门,姓名,学历 from  employee where 员工编号 in (select 部门经理 from department)');
Query1.Open;
Label1.Caption:='操作提示：查询各个部门经理的姓名和学历';
end;

procedure TForm1.BitBtn8Click(Sender: TObject);
begin
Query1.Close;
Query1.SQL.Clear;
Query1.SQL.Add('Select 姓名, 工资 from employee order by 工资 asc'); //升序
//Query1.SQL.Add('Select 姓名, 工资 from employee order by 工资 desc');   //降序
Query1.Open;
Label1.Caption:='操作提示：按工资字段以递增的顺序返回所有雇员的姓名和工资两列数据';
end;

procedure TForm1.BitBtn9Click(Sender: TObject);
begin
Query1.Close;
Query1.SQL.Clear;
Query1.SQL.Add(' Select 所在部门, count(员工编号) as 部门人数 , avg(工资) as 平均工资,max(工资) as 最高工资,min(工资) as 最低工资 from  employee  group by 所在部门');
Query1.Open;
Label1.Caption:='操作提示：对部门进行分组，统计各个部门的人数、平均工资、最高工资、最低工资';
end;

procedure TForm1.BitBtn10Click(Sender: TObject);
begin
Query1.Close;
Query1.SQL.Clear;
Query1.SQL.Add(' Select 所在部门, count(员工编号) as 部门人数 from  employee  group by 所在部门 having count(员工编号)>4');
Query1.Open;
Label1.Caption:='操作提示：对部门进行分组，返回部门人数大于4的所在部门和部门人数两列数据';
end;

end.