unit6.pas

能够动态的实现数据库表的创建

unit Unit6;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DB, ADODB, Mask, DBCtrls, main,StdCtrls, Grids, DBGrids, ExtCtrls,
  Buttons;

type
  Tcourse = class(TForm)
    Panel1: TPanel;
    DBGrid1: TDBGrid;
    Edit1: TEdit;
    Edit2: TEdit;
    Label2: TLabel;
    ADOQuery1: TADOQuery;
    DataSource1: TDataSource;
    DataSource2: TDataSource;
    Label1: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Edit3: TEdit;
    Edit4: TEdit;
    Label5: TLabel;
    DBLookupComboBox1: TDBLookupComboBox;
    ADOQuery2: TADOQuery;
    ADOQuery3: TADOQuery;
    BitBtn1: TBitBtn;
    BitBtn2: TBitBtn;
    BitBtn3: TBitBtn;
    procedure DBGrid1DblClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure BitBtn1Click(Sender: TObject);
    procedure BitBtn2Click(Sender: TObject);
    procedure BitBtn3Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  course: Tcourse;

implementation

{$R *.dfm}

procedure Tcourse.DBGrid1DblClick(Sender: TObject);
begin
edit1.text:=adoquery1.fieldbyname('课程名称').asstring;
edit2.Text:=adoquery1.fieldbyname('学时').asstring;
edit3.Text:=adoquery1.fieldbyname('学分').asstring;
edit4.text:=adoquery1.fieldbyname('任课教师').asstring;
dblookupcombobox1.keyvalue:=adoquery1.fieldbyname('系名称').asstring;
BitBtn2.Enabled:=true;
end;

procedure Tcourse.FormCreate(Sender: TObject);
begin
  BitBtn2.Enabled:=false;
end;

procedure Tcourse.BitBtn1Click(Sender: TObject);
var sql:string;
begin
   ADOquery1.close;
   ADOquery1.sql.clear;
   ADOquery1.sql.add('select * from 课程 where 课程名称='''+edit1.text+'''');
   ADOquery1.open;
   if ADOquery1.recordcount>0 then
   begin
      showmessage('该课程已经存在');
      edit1.selectall;
      ADOquery1.close;
      ADOquery1.sql.clear;
      ADOquery1.sql.add('select * from 课程');
      ADOquery1.open;
        exit;
   end;

if(edit1.Text='')or(edit2.Text='')or(edit3.Text='')or(edit4.Text='')or(dblookupcombobox1.keyvalue=null)then
begin
 application.MessageBox('请输入完整的信息','提示',mb_ok);
 exit;
end;
with ADOquery1 do
begin
append;
fieldvalues['课程名称']:=edit1.Text;
fieldvalues['学时']:=edit2.Text;
fieldvalues['学分']:=edit3.Text;;
fieldvalues['任课教师']:=edit4.Text;
fieldvalues['系名称']:=dblookupcombobox1.keyvalue;
 post;
    ADOquery1.close;
   ADOquery1.sql.clear;
   ADOquery1.sql.add('select * from 课程');
   ADOquery1.open;
 end;

  sql:='alter table '+dblookupcombobox1.keyvalue+' add['+Edit1.Text+'] varchar(5)';
  Adoquery3.close;
  Adoquery3.sql.Clear ;
  Adoquery3.SQL.add(sql);
  Adoquery3.Execsql;

    BitBtn2.enabled:=false;
end;

procedure Tcourse.BitBtn2Click(Sender: TObject);
  var
i:integer;
sql:string;
begin
i:=application.MessageBox('确定要删除吗？','删除提示',mb_YesNO);
 if i=7 then
 exit;
 ADOquery1.Delete;
   ADOquery1.close;
   ADOquery1.sql.clear;
   ADOquery1.sql.add('select * from 课程');
   ADOquery1.open;
   sql:='alter table '+dblookupcombobox1.keyvalue+' drop['+Edit1.Text+']';
   Adoquery3.close;
   Adoquery3.sql.Clear ;
   Adoquery3.SQL.add(sql);
   Adoquery3.Execsql;
   BitBtn2.Enabled:=false;
end;
procedure Tcourse.BitBtn3Click(Sender: TObject);
begin
  close;
end;

end.