在绑定情况下输入新记录怎样来判断主键值重复？

[dqiuqiu]

如：表Table1中有MyNo字段为主键,我用DATA CONTROLS中的控件输入记录，当在点下〈保存〉按钮时(调用POST方法），如Myno字段有重复值时会出错。想请教一下怎样才能判断有重复值而不进行保存。用什么方法或事件解决？能给出代码示例最好。（一定得用绑定）。

[yexiaofeng]

使用tabel.LOCATE
具体用法看delphi帮助

[gwbasic]

我也没好办法,只在保存前用
Query 查一下是有此记录,如有,则给出提示信息

With ADOQuery do
begin
if Active then Close;
SQL.Clear;
SQL.Add('select MyNo from MyTable where MyNo=' + IntToStr(MyNo));
Open;
If not Eof then
begin
Close;
ShowMessage('主键重复');
Abort;
end;
Close;
end;

[wzs_wzs123]

我同意楼上的,先上数据库中查一下,看有没有输入的值.

[dqiuqiu]

谢谢各位参与。问题就在于因为是绑定，用locate方法的时候，记录指针一移动,数据库里已添加了这笔记录，如果是主键重复，就会出现错误。所以得用什么办法来解决？

[dqiuqiu]

顺便问一下，不知大家在做单记录输入的表单时（字段很多），是用控件绑定还是非绑定呢？

[dqiuqiu]

请大家再帮帮我吧·！

[zhhyoushen]

用locate吧，看一下，我想会有帮助的
function Locate(const KeyFields: string; const KeyValues: Variant; Options: TLocateOptions): Boolean; virtual;

Description

This function returns False, indicating that a matching record was not found and the cursor is not repositioned.

Descendant classes override this method so that it locates the record where the fields identified by the comma-delimited string KeyFields have the values specified by the Variant or Variant array KeyValues. Options indicates whether the search is case insensitive and whether partial matches are supported. Locate should return True if a record is found that matches the specified criteria and the cursor repositioned to that record.

[gwbasic]

绑定会更容易点,
以前用非绑定,我现在改用绑定