如何在app.config文件中指定连接字符串 [英] how to specify connection string in app.config file

问题描述

private void button1_Click(object sender, EventArgs e)
        {
            string str = ConfigurationSettings.AppSettings["ConnectionString"];


            using (SqlConnection connection = new SqlConnection(str))
            {     try 
            {

                connection.Open();   ---throwing error here saying instance failure
            }   
            catch (System.Data.SqlClient.SqlException ex)
            {   
                  
                return;
            } 
                string selectCommandText = "SELECT * FROM tmptblUserProfile";   
                using (SqlDataAdapter adapter = new SqlDataAdapter(selectCommandText, connection))
                {
                    using (DataTable table = new DataTable("tmptblUserProfile")) 
                {             adapter.Fill(table);           
                    
                    StringBuilder commaDelimitedText = new StringBuilder();
                    commaDelimitedText.AppendLine("col1|col2|col3|col4|col5|col6col7|col8|col9|col10|col11|col12|col13|col14|col15");         
                    foreach (DataRow row in table.Rows) {
                        string value = string.Format("{0}|{1}|{2}|{3}|{4}|{5}{6}|{7}|{8}{9}|{10}|{11}{12}|{13}|{14}", row[0], row[1], row[2], row[3], row[4], row[5], row[6], row[7], row[8], row[9], row[10], row[11], row[12], row[13], row[14]);                 
                        commaDelimitedText.AppendLine(value);         
                    }        
                    File.WriteAllText(@"C:\Documents and Settings\aj99823\Desktop\amal101.txt", commaDelimitedText.ToString());    
                }  
            }

            } 
        }

在app.config中，我指定为

in the app.config i specified as

<configuration>
  <appsettings>
 <add key="ConnectionString">
 value="Data Source=CSZ-PCS43132\\SQLEXPRESS;Initial Catalog=test;Integrated Security=True"
 />
 </add></appsettings>
  </configuration>

执行此语句时，它抛出一个错误，说明实例失败.任何人都可以帮助我.............

it is throwing one error saying instance failure while executing this statement.can anyone plss help me.............

推荐答案

问题与您的配置文件无关，问题出在您的SQL Server实例名称上.检查CSZ-PCS43132 \\ SQLEXPRESS是否为有效的SQL Server实例. (此处CSZ-PCS43132是您的PC/服务器名称，而SQLEXPRESS是您的实例名称)

The problem is not with your config file, the problem is with your SQL Server instance name. Check if CSZ-PCS43132\\SQLEXPRESS is a valid SQL Server instance. (Here CSZ-PCS43132 is your PC/Server name and SQLEXPRESS is your instance name)

连接字符串的指定方式与在appconfig.ex
中的操作方式相同

connection string is specified just like how you did in appconfig.ex

<connectionStrings>
   <clear />
   <add name="Local" connectionString="Data Source=MyPC;Database=Northwind;user=sa;password=pass;" />
   </connectionStrings>

似乎您的连接字符串不正确.您可以尝试使用相同的凭据打开SSMS.

It seems like your connection string is not correct.You can try to open SSMS using same credential.

您的问题是因为在"\\"中您的连接字符串应为
CSZ-PCS43132 \ SQLEXPRESS;初始目录=测试;集成安全性=真

如果有帮助，请将其标记为已回答

Your problem is because of in "\\" your connection string should be
CSZ-PCS43132\SQLEXPRESS;Initial Catalog=test;Integrated Security=True

Mark it as answered if it helps

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