Question

I’m using C# in .NET 2.0 and I’m trying to access and manipulate a database. I can read as many times from the DB as I want and everything works, but as soon as I try to insert an item I get the following error message:

ExecuteNonQuery requires an open and available Connection. The connection's current state is closed.

I’ve tried to look this up, but the fixes I was able to find either didn’t work or weren’t applicable.

I have the following code:

using (SqlConnection conn = new SqlConnection(SQLConnectionString))
{
    SqlDataAdapter dataAdapter = new SqlDataAdapter("SELECT [Col1] FROM [Table1] WHERE [Col2]='" + val2 + "'", conn);
    DataSet dataSet = new DataSet();
    dataAdapter.Fill(dataSet);

    if (dataSet.Tables.Count == 0 || dataSet.Tables[0].Rows.Count != 1)
    {
        SqlCommand cmd = new SqlCommand("INSERT INTO [Table1] ([Col1], [Col2]) VALUES ('" + val1 + "', '" + val2 + "')", conn);
        cmd.ExecuteNonQuery();
    }
}

Note: I’m sure I have permissions set up properly, since Visual Studio can insert with the same SQLConnectionString. Also, I am still fairly new to databases, so if I’m doing anything blantently wrong, please let me know.

Thanks.

Answer 1

You don’t appear to be opening the connection to perform your update (the exception tells you this).

Try this

SqlCommand cmd = new SqlCommand("INSERT INTO [Table1] ([Col1], [Col2]) VALUES ('" + val1 + "', '" + val2 + "')", conn);
            conn.Open();    
            cmd.ExecuteNonQuery();
            conn.Close();

You can get more details and working example on MSDN at http://msdn.microsoft.com/en-us/library/sd2728ad.aspx