小编典典

ExecuteNonQuery:连接属性尚未初始化。

c#

下午,所以我在这个问题上待了好几个小时,无法真正克服最后一个困难。以下是我正在编写的该程序的代码:

using System;  
using System.Collections.Generic;  
using System.Linq;  
using System.Text;  
using System.Diagnostics;  
using System.Data;  
using System.Data.SqlClient;  
using System.Configuration;

namespace Test  
{  
  class Program  
  {  
    static void Main()  
    {  
      EventLog alog = new EventLog();  
      alog.Log = "Application";  
      alog.MachineName = ".";  
      foreach (EventLogEntry entry in alog.Entries)  
      {  
       SqlConnection connection1 = new SqlConnection(@"Data Source=.\sqlexpress;Initial Catalog=syslog2;Integrated Security=True");  
       SqlDataAdapter cmd = new SqlDataAdapter();  
       cmd.InsertCommand = new SqlCommand("INSERT INTO Application VALUES (@EventLog, @TimeGenerated, @EventType, @SourceName, @ComputerName, @InstanceId, @Message) ");  
       cmd.InsertCommand.Parameters.Add("@EventLog",SqlDbType.VarChar).Value = alog.Log;  
       cmd.InsertCommand.Parameters.Add("@TimeGenerated", SqlDbType.DateTime).Value = entry.TimeGenerated;  
       cmd.InsertCommand.Parameters.Add("@EventType", SqlDbType.VarChar).Value = entry.EntryType;  
       cmd.InsertCommand.Parameters.Add("@SourceName", SqlDbType.VarChar).Value = entry.Source;  
       cmd.InsertCommand.Parameters.Add("@ComputerName", SqlDbType.VarChar).Value = entry.MachineName;  
       cmd.InsertCommand.Parameters.Add("@InstanceId", SqlDbType.VarChar).Value = entry.InstanceId;  
       cmd.InsertCommand.Parameters.Add("@Message", SqlDbType.VarChar).Value = entry.Message;  
       connection1.Open();  
       cmd.InsertCommand.ExecuteNonQuery();  
       connection1.Close();  
      }   
    }  
  }  
}

该代码可以正常编译,没有错误或警告,但是当我运行它时,只要它到达cmd.InsertCommand.ExecuteNonQuery();就可以了。我收到以下错误:

ExecuteNonQuery:连接属性尚未初始化。

关于我错过的任何想法?


阅读 582

收藏
2020-05-19

共1个答案

小编典典

您需要将连接分配给SqlCommand,可以使用构造函数属性

cmd.InsertCommand = new SqlCommand("INSERT INTO Application VALUES (@EventLog, @TimeGenerated, @EventType, @SourceName, @ComputerName, @InstanceId, @Message) ");
cmd.InsertCommand.Connection = connection1;

我强烈建议对using-statement实现IDisposable类似的任何类型使用SqlConnection,它还会关闭连接:

using(var connection1 = new SqlConnection(@"Data Source=.\sqlexpress;Initial Catalog=syslog2;Integrated Security=True"))
using(var cmd = new SqlDataAdapter())
using(var insertCommand = new SqlCommand("INSERT INTO Application VALUES (@EventLog, @TimeGenerated, @EventType, @SourceName, @ComputerName, @InstanceId, @Message) "))
{
    insertCommand.Connection = connection1;
    cmd.InsertCommand = insertCommand;
    //.....
    connection1.Open();
    // .... you don't need to close the connection explicitely
}

除此之外,你并不需要创建一个新的连接,并DataAdapter在每个条目foreach,即使创建,打开和关闭连接并 不能
意味着ADO.NET将创建,打开和关闭一个 物理
连接,但只是眺望用于可用连接的连接。但是,这是不必要的开销。

2020-05-19