Question

我创建了一个名为myT的简单表，我正在尝试从c＃代码中打印数据，但我正在进行exseption，这是我的c＃代码：

using (SqlConnection conn = new SqlConnection())
            {                                //LAPTOP-69PFVE6D
                conn.ConnectionString = "Server =LAPTOP-69PFVE6D ; Database = Database1; Integrated Security = true";
                conn.Open();

                SqlCommand command = new SqlCommand("SELECT * FROM dbo.myT", conn);

                // Add the parameters.
                //command.Parameters.Add(new SqlParameter("0", 1));

                using (SqlDataReader reader = command.ExecuteReader())
                {                   
                    while (reader.Read())
                    {
                        // Console.WriteLine(String.Format("{0} \t | {1}",
                        // reader[0], reader[1]));
                        Console.WriteLine(reader.GetString(0));
                    }
                }              

            }

以下是截图：

enter image description here

这是我的App.config：

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
  </startup>
  <connectionStrings>
    <add name="SqlTest_CSharp.Properties.Settings.connectionStr"
           connectionString="Server = LAPTOP-69PFVE6D; Database = Database1; Integrated Security = true"
           providerName="System.Data.SqlClient" />
  </connectionStrings>
</configuration>

以下是例外：

חריג שאינו מטופל: System.Data.SqlClient.SqlException: אירעה שגיאה הקשורה לרשת או שגיאה ספציפית למופע במהלך יצירת חיבור ל- SQL Server. השרת לא נמצא או שאינו נגיש. ודא ששם המופע נכון וש- SQL Server מוגדר לאפשר חיבורים מרחוק. (provider: Named Pipes Provider, error: 40 - לא הייתה אפשרות לפתוח חיבור ל- SQL Server) ---> System.ComponentModel.Win32Exception: The system cannot find the file specified
   --- סוף רכיב מעקב אחר מחסנית של מצב חריג פנימי ---
   ב-  System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, DbConnectionPool pool, String accessToken, Boolean applyTransientFaultHandling)
   ב-  System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
   ב-  System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
   ב-  System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   ב-  System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   ב-  System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   ב-  System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   ב-  System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
   ב-  System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   ב-  System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
   ב-  System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
   ב-  System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
   ב-  System.Data.SqlClient.SqlConnection.Open()
   ב-  SqlTest_CSharp.Program.Main(String[] args) ב- C:\Users\BadAss\Downloads\SqlTest_CSharp\SqlTest CSharp\SqlTest CSharp\Program.cs:שורה 14
Press any key to continue . . .

无法从数据库打印数据

0 个答案: