mORMot学习笔记2-2种方式查询数据

本例使用SqlServer

第一种方式结果放入Memo控件,,需要引用SynCommons, SynDB, SynOleDb;

procedure TForm1.Button1Click(Sender: TObject);
var
  DbConn: TOleDBMSSQLConnectionProperties;
  strSql: string;
  rows: ISQLDBRows;begin
  DbConn := TOleDBMSSQLConnectionProperties.Create(127.0.0.1, ReportServer, sa, Sa123);
  strSql := SELECT r.RoleName, r.Description FROM Roles AS r;
  rows := DbConn.ExecuteInlined(strSql, True);
  if rows <> nil then
  begin
    memo1.Clear;
    memo1.Lines.BeginUpdate;     while rows.Step() do
    begin
      Memo1.Lines.Add(rows.ColumnString(RoleName) + - + rows.ColumnString(Description));
    end;
  end;
  Memo1.Lines.EndUpdate;
end;

procedure TForm1.Button1Click(Sender: TObject); var DbConn: TOleDBMSSQLConnectionProperties; strSql: string; rows: ISQLDBRows;begin DbConn := TOleDBMSSQLConnectionProperties.Create(127.0.0.1, ReportServer, sa, Sa123); strSql := SELECT r.RoleName, r.Description FROM Roles AS r; rows := DbConn.ExecuteInlined(strSql, True); if rows <> nil then begin memo1.Clear; memo1.Lines.BeginUpdate; while rows.Step() do begin Memo1.Lines.Add(rows.ColumnString(RoleName) + - + rows.ColumnString(Description)); end; end; Memo1.Lines.EndUpdate; end;

第二种方式,返回数据集到DBGrid控件,需要引用SynCommons, SynDB, SynOleDb, SynDBMidasVCL;

procedure TForm1.Button2Click(Sender: TObject);
var
  DbConn: TOleDBMSSQLConnectionProperties;
  ds: TSynDBDataSet;
begin
  DbConn := TOleDBMSSQLConnectionProperties.Create(127.0.0.1, ReportServer, sa, Sa123);
  ds := TSynDBDataSet.Create(nil);
  ds.Connection := DbConn;
  ds.CommandText := SELECT r.RoleName, r.Description FROM Roles AS r;
  ds.Open;
  DataSource1.DataSet := ds;
  //ds不能在这里释放不然结果就不显示了
end;

procedure TForm1.Button2Click(Sender: TObject); var DbConn: TOleDBMSSQLConnectionProperties; ds: TSynDBDataSet; begin DbConn := TOleDBMSSQLConnectionProperties.Create(127.0.0.1, ReportServer, sa, Sa123); ds := TSynDBDataSet.Create(nil); ds.Connection := DbConn; ds.CommandText := SELECT r.RoleName, r.Description FROM Roles AS r; ds.Open; DataSource1.DataSet := ds; //ds不能在这里释放不然结果就不显示了 end;

两种方式执行结果

本例使用SqlServer 第一种方式结果放入Memo控件,,需要引用SynCommons, SynDB, SynOleDb; procedure TForm1.Button1Click(Sender: TObject); var DbConn: TOleDBMSSQLConnectionProperties; strSql: string; rows: ISQLDBRows;begin DbConn := TOleDBMSSQLConnectionProperties.Create(127.0.0.1, ReportServer, sa, Sa123); strSql := SELECT r.RoleName, r.Description FROM Roles AS r; rows := DbConn.ExecuteInlined(strSql, True); if rows <> nil then begin memo1.Clear; memo1.Lines.BeginUpdate; while rows.Step() do begin Memo1.Lines.Add(rows.ColumnString(RoleName) + - + rows.ColumnString(Description)); end; end; Memo1.Lines.EndUpdate; end; 第二种方式,返回数据集到DBGrid控件,需要引用SynCommons, SynDB, SynOleDb, SynDBMidasVCL; procedure TForm1.Button2Click(Sender: TObject); var DbConn: TOleDBMSSQLConnectionProperties; ds: TSynDBDataSet; begin DbConn := TOleDBMSSQLConnectionProperties.Create(127.0.0.1, ReportServer, sa, Sa123); ds := TSynDBDataSet.Create(nil); ds.Connection := DbConn; ds.CommandText := SELECT r.RoleName, r.Description FROM Roles AS r; ds.Open; DataSource1.DataSet := ds; //ds不能在这里释放不然结果就不显示了 end; 两种方式执行结果