连接数据库时遇到的一个大问题 [英] A big problem in connecting to database

问题描述

嗨！



我的程序工作得非常好，直到昨天，当我运行它时，我的网格视图从sql数据库的数据表中获取数据源没有表现出什么。我试图理解断点有什么问题，我明白程序会跳过这部分并且不会连接到数据库：

Hi!

My program worked very well untill yesterday, when i was running it, my grid view that got data source from a data table of sql data base didn't show any thing. i tried to understand what was wrong with a break point, i understood that program jumps this part and doesn't connect to data base:

SqlConnection cs = new SqlConnection("Data Source=.\\local_2008; Initial Catalog=Library; User Id=userLibrary; Password=123456");

有趣的部分是，它没有显示任何错误，当我使用try / catch异常并没有显示任何关于错误的内容。

让我疯狂的是当我在这一行使用断点来获取错误并选择部件并使用Quick Watch显示没有错误，然后我点击F5继续该程序工作，并显示表!!!!!!

请帮我解决这个令人难以置信的问题



谢谢

the interesting part is that, it doesn't show any error and when i used try/catch the exception doesn't show anything about error.
and what made me crazy is that when i use a breakpoint on this line to get the error and select the part and use Quick Watch it shows no error and then i click f5 to continue the program works as it should and shows the table!!!!!!
please help me to solve this unbelievable problem

thank you

SqlConnection cs = new SqlConnection("Data Source=.\\local_2008; Initial Catalog=Library; User Id=userLibrary; Password=123456");
SqlCommand cmd = new SqlCommand("searchBook", cs);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add("@biCode", SqlDbType.Int).Value = biCode;
cmd.Parameters.Add("@biName", SqlDbType.NVarChar).Value = biName;
cmd.Parameters.Add("@biAuthor", SqlDbType.NVarChar).Value = biAuthor;
cmd.Parameters.Add("@biTranslator", SqlDbType.NVarChar).Value = biTranslator;
cmd.Parameters.Add("@biPublisher", SqlDbType.NVarChar).Value = biPublisher;
cmd.Parameters.Add("@biSubject", SqlDbType.Int).Value = biSubject;
cmd.Parameters.Add("@biStatus", SqlDbType.Int).Value = biStatus;
cmd.Parameters.Add("@biIssueDate", SqlDbType.VarChar).Value = biIssueDate;
cmd.Parameters.Add("@biLink", SqlDbType.NVarChar).Value = biLink;
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);

return dt;

好​​消息：

我再次使用app.config并且旧的错误没有再次发生但现在它从da.Fill（dt）跳出来

实例失败

错误我现在该怎么办？



新部分：

Good news:
I used app.config again and the old error didn't happened again but now it jumps out from da.Fill(dt) with
Instance failure
error now what should i do?

new part:

string str = System.Configuration.ConfigurationManager.AppSettings["cs"];
                SqlConnection cs = new SqlConnection(str);

推荐答案

对于dataadapter，您尚未传递连接字符串。尝试

for dataadapter you have not passed the connectionstring. try

DataAdapter da=New DataAdapter(query,ConString)

它应该可以工作。您无需手动打开数据适配器的连接。它自动完成。

it should work.and you need not manually open a connection for a dataadapter.it does that automatically.

尝试如下...

Try like below...

SqlConnection cs = new SqlConnection("Data Source=.;Initial Catalog=Library;User ID=userLibrary;Password=123456");

特别感谢谁的帮助



我不知道第一个问题是什么，但是当我使用app.config时它就解决了。



和第二部分

来自连接字符串。当你使用app.config时要小心，因为它是XML并且不会转到//并且你应该自己动手：D

BYE BYE

special thanks to who help

I don't know what was the first problem but when i used app.config it solved.

and about the second part
it was from the connect string. be careful when you use app.config because it's XML and doesn't turn // to / and you should do that your self :D
BYE BYE

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