组合框相关查询 [英] combo box related query

问题描述

我正在使用Vb.net前端Sharp Development和.net Framework 3.5，数据库msaccess.

我的编码中有一个模块，用于在组合框中显示客户端的所有名称.

我在表单加载时提取名称并显示它.它工作正常.

现在，我想要的是，当用户键入字符b时，将创建一个下拉类型的东西，并且应显示所有以b开头的名称，并首先将重点放在第一条记录上.现在，如果用户按a，则应显示所有以ba开头的名称.

我知道我可以使用％查询来重新填充数据库，但是由于数据库名称很多，所以我不想这样做.

有什么建议吗?

I am using Vb.net front end sharp develop and .net framework 3.5, database msaccess.

There is a module in my coding where I am showing all the names of the client in the combobox.

I''m extracting the names at form load and displaying it. It is working properly.

Now what I want is when the user type character b then a drop down type something should be created and all the name starting with b should be displayed with initial focus on first record. Now when if user press a then all name starting with ba should be displayed.

I know I can repopulate the database using like % query but since the database will have lakhs of name I don''t want to do so.

Any suggestion ?

推荐答案

如果您有一个拥有数百万条记录的大型数据库，则最好使用虚拟下拉列表.当用户开始键入时，请等待大约500毫秒，然后仅对以输入文本开头的名称进行DB提取.您需要异步检索数据以防止UI冻结. 500毫秒的等待时间是为了节省不必要的提取.

If you have a large database with millions of records, it may make better sense to have a virtual drop down. When the user starts typing, wait for about 500 ms and then do a DB fetch for just those names that start with the entered text. You''d need to retrieve the data asynchronously to prevent a UI freeze-up. And the 500ms wait is to save on unwanted fetches.

我建​​议重新设计.我认为访问似乎不适合大型应用程序.同样，拥有具有这么多值的组合框也没有意义.我建议使用文本框和按钮进行搜索.

I would suggest redesign. I do not think access is suitable for huge applications as your seems to be. Also, it does not makes sense to have a combobox with those many values. I would suggest a search using textbox and a button.

您能解释一下如何添加虚拟组合下拉菜单.

can u explain how to add virtual combo drop.

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