“从类型dbnull到日期类型的转换无效"? [英] "Conversion from type dbnull to type date is not valid"?

问题描述

我试图为我的NYSC Biometrics注册手指，但它一直显示从DBNull类型到Date类型的转换无效"?

我尝试过的事情:

我已经尝试过使用google寻求解决方案，但没有找到正确的答案.

I tried to enroll my finger for NYSC Biometrics but it keep on showing "Conversion from type DBNull to type Date is not valid"?

What I have tried:

I have tried google for solution but i did not see the right answer

推荐答案

如果您尝试编写自己的软件，那么没有相关的代码，没有人可以帮助您碎片.
因此，这取决于您.
幸运的是，您拥有一个可用的工具，该工具可以帮助您查找正在发生的事情:调试器.如何使用它取决于您的编译器系统，但是快速使用Google作为IDE和调试器"的名称应该可以为您提供所需的信息.

在函数的第一行上放置一个断点，然后通过调试器运行代码.然后查看您的代码和数据，并确定应该手动执行的操作.然后，单行检查每一行，以确保您期望发生的事情确实是正确的.如果不是，那就是您遇到问题时，可以回溯(或再次运行并仔细查看)以找出原因.
抱歉，但是我们不能为您做到这一点-是时候让您学习一种新的(也是非常非常有用的)技能:调试！

如果您尝试使用制造商提供的软件，那么我们将完全无济于事.您应该与创建它的人交谈- NYSC [

If you are trying to write your own software, then nobody can help you without the relevant code fragments.
So, it''s going to be up to you.
Fortunately, you have a tool available to you which will help you find out what is going on: the debugger. How you use it depends on your compiler system, but a quick Google for the name of your IDE and "debugger" should give you the info you need.

Put a breakpoint on the first line in the function, and run your code through the debugger. Then look at your code, and at your data and work out what should happen manually. Then single step each line checking that what you expected to happen is exactly what did. When it isn''t, that''s when you have a problem, and you can back-track (or run it again and look more closely) to find out why.

Sorry, but we can''t do that for you - time for you to learn a new (and very, very useful) skill: debugging!

If you are trying to use software provided by the manufacturer, then we can''t help at all. You should talk to the people who created it - NYSC[^] - they should provide technical support and will know more about their product than we will.

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