What are the potential issues using this static class

Question

Here is my sample code:

public static class MySqlHelper
{
    private static string constring = ConfigurationManager.ConnectionStrings["MyConnString"].ConnectionString;

    public static int ExecuteNonQuery(string mysqlquery)
    {
        SqlConnection conn = new SqlConnection(connString);
        SqlCommand cmd = new SqlCommand(mysqlquery, conn);
        int result;

        try
        {
            conn.Open();
            result= cmd.ExecuteNonQuery();
        }
        finally
        {
            conn.Close();
        }
        return result;
    }
}

Usage: MySqlHelper.ExecuteNonQuery("select * from customers");

I would like to know the issues using this static class.

I can change my class as mentioned here but I have been using this class in couple of websites and I will need couple days to change it in every place and test it out.

Thanks for any inputs.

Edit: Updated the code. Does that make difference on the answers provided? Sorry, I should have posted in the beginning.

Answer 1

I am assuming the connection string doesnt change during execution (you might want to make it readonly). Since there is no other shared state shown in the question, there are no real problems.

However, if you have any shared state you have a huge threading problem. And if you have shared connections you have an even bigger problem.

But as written, with no significant static fields: no problem.