连接未初始化

Question

我有一个快速的问题,我的连接没有初始化.

当我调用create方法时,我传入了一堆varnames,比如"ABC,XYZ等".

在foreach的第一次传递中,存储过程被正确调用,并且工作正常.但在第二遍,我得到一个"Connectionstring属性尚未初始化.

我应该在循环之外移动myConn.open和myConn.close吗？

我的代码:

public bool Create()
{
        bool isSuccess = true;

        ConnectionStringSettings myConnectionStringSetting = ConfigurationManager.ConnectionStrings[0];
        DbProviderFactory dbFactory = DbProviderFactories.GetFactory(myConnectionStringSetting.ProviderName);

        DbConnection myConn = dbFactory.CreateConnection();
        myConn.ConnectionString = myConnectionStringSetting.ConnectionString;

        DataTable myDataTable = new DataTable();

        string[] varNamesArray = m_variableNames.Split(',');

        foreach (string varName in varNamesArray)
        {
            string vn = varName.Trim();

            //stored procedure

            DbCommand myCommand = dbFactory.CreateCommand();
            myCommand.CommandText = "s_LockVariables";
            myCommand.CommandType = CommandType.StoredProcedure;
            myCommand.Connection = myConn;

            //variables            

            DbParameter param1 = myCommand.CreateParameter();
            param1.ParameterName = "@varName";
            param1.DbType = DbType.String;
            param1.Value = vn;
            myCommand.Parameters.Add(param1);

            DbParameter param2 = myCommand.CreateParameter();
            param2.ParameterName = "@datasetID";
            param2.DbType = DbType.Int32;
            param2.Value = m_datasetID;
            myCommand.Parameters.Add(param2);

            DbParameter param3 = myCommand.CreateParameter();
            param3.ParameterName = "@userID";
            param3.DbType = DbType.Int32;
            param3.Value = m_userID;
            myCommand.Parameters.Add(param3);

            DbParameter param4 = myCommand.CreateParameter();
            param4.ParameterName = "@currentTime";
            param4.DbType = DbType.DateTime;
            param4.Value = DateTime.Now;
            myCommand.Parameters.Add(param4);

            try
            {
                using (myConn)
                {
                    myConn.Open();
                    myCommand.ExecuteNonQuery();
                    myConn.Close();
                }
            }
            catch (Exception e)
            {
                isSuccess = false;
                throw new Exception(e.Message);
                //TODO:  catch data error

                return isSuccess;
            }
        }

        return isSuccess;
    }

Answer 1

你处置myConn的内foreach这里循环:

using (myConn)
{
    myConn.Open();
    myCommand.ExecuteNonQuery();
    myConn.Close();
}

我建议你只需改变它就可以在那里声明变量:

using (DbConnection myConn = dbFactory.CreateConnection())
{
    myConn.ConnectionString = myConnectionStringSetting.ConnectionString;
    myConn.Open();
    myCommand.Connection = myConn;
    myCommand.ExecuteNonQuery();
    // Closed automatically due to being disposed
}

或者只是在循环外面有一个using语句- 你也可以为所有命令使用相同的连接,对吧？