jladd jladd - 2 months ago 11
C# Question

ExecuteNonQuery: Connection property has not been initialized.

Afternoon,
So I have been at this one issue for hours and can't really get past this last hump. Below is the code for this program that I am writing:

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();
}
}
}
}


The Code compiles fine without error or warning but when i go to run it, as soon as it gets to cmd.InsertCommand.ExecuteNonQuery(); I get the following error:


ExecuteNonQuery: Connection property has not been initialized.


Any ideas on what I missed?

Answer

You need to assign the connection to the SqlCommand, you can use the constructor or the property:

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

I strongly recommend to use the using-statement for any type implementing IDisposable like SqlConnection, it'll also close the connection:

using(var connection1 = new SqlConnection(@"Data Source=.\sqlexpress;Initial Catalog=syslog2;Integrated Security=True"))
{
    SqlDataAdapter 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
    }
}

Apart from that you don't need to create a new connection and DataAdapter for every entry in the foreach, even if creating, opening and closing a connection does not mean that ADO.NET will create, open and close a physical connection but just looks into the connection-pool for an available connection. Nevertheless it's an unnecessary overhead.

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