点确认时报错

Question

procedure TFrmChangePwd.btnEnterClick(Sender: TObject);
begin
  With DmBasic Do
    Begin
      qryChangePwd.Close;
      qryChangePwd.Sql.Clear;   
      qryChangePwd.Sql.Add('SELECT * FROM STYLEUSER WHERE USERID='''+qryLogin.FieldByName('USERID').Value+'''');//这样写有没错,但可以过编译
      qryChangePwd.Open;
      If qryChangePwd.Recordset.RecordCount>0 Then
        qryChangePwd.SQL.Add('SELECT * FROM STYLEUSER WHERE PWD='''+EdOld.Text+'''');
          If qryChangePwd.Recordset.RecordCount>0 Then
            EdNew.SetFocus;
              If EdNew.Text<>'' Then
                EdEnter.SetFocus;
                  If EdEnter.Text=EdNew.Text  Then
                    Begin
                    qryChangePwd.SQL.Add('UPDATE STYLEUSER SET PWD='''+EdEnter.Text+''' WHERE USERID='''+qryLogin.FieldByName('USERID').Value+'''' );
                    qryChangePwd.ExecSql;
                    End
                  Else
                     ShowMessage('两次密码不一致!');
                  End;
                  End;end.

Answer 1

qryLogin.FieldByName('USERID').Asstring，如果userid字段是数值型的，就别加引号

Answer 2

  qryChangePwd.Sql.Add(' SELECT * FROM STYLEUSER WHERE USERID='''+trim(qryLogin.FieldByName('USERID').AsString)+''' ');
qryChangePwd.Close;
  qryChangePwd.Sql.Clear; 
qryChangePwd.SQL.Add('UPDATE STYLEUSER SET PWD='''+EdEnter.Text+''' WHERE USERID='''+qryLogin.FieldByName('USERID').Value+'''' );
  qryChangePwd.ExecSql;

Answer 3

你用的是同一個ado,再次使用時，先用close和clear之前的再使用

Answer 4

是的,就是每次用时先Close和Close就可以了..
begin
  With DmBasic Do
    Begin
      qryChangePwd.Close;
      qryChangePwd.Sql.Close;   //SELECT NAME FROM STYLEUSER
      qryChangePwd.Sql.Add('SELECT * FROM STYLEUSER WHERE USERID='''+Trim(qryLogin.FieldByName('USERID').Value)+'''');
      qryChangePwd.Open;
      If qryChangePwd.Recordset.RecordCount>0 Then
         qryChangePwd.Close;
         qryChangePwd.Sql.Clear;
         qryChangePwd.SQL.Add('SELECT * FROM STYLEUSER WHERE PWD='''+EdOld.Text+'''');
         qryChangePwd.Open;
          If qryChangePwd.Recordset.RecordCount>0 Then
            EdNew.SetFocus;
              If EdNew.Text<>'' Then
                EdEnter.SetFocus;
                  If EdEnter.Text=EdNew.Text  Then
                    Begin
                    qryChangePwd.Close;
                    qryChangePwd.Sql.Clear;
                    qryChangePwd.SQL.Add('UPDATE STYLEUSER SET PWD='''+EdEnter.Text+''' WHERE USERID='''+qryLogin.FieldByName('USERID').Value+'''' );
                    qryChangePwd.ExecSql;
                    End
                  Else
                     ShowMessage('两次密码不一致!');
                  End;
                  End;