封装一个通用的数据库操作类

最近写一个项目，我开发的方式首先设计数据库，然后用网上免费的代码生成软件CodePlus V2.0生成mode对象，同时封装操作方法，在与数据库操作方面我封装了一个数据操作类，很方便，贡献出来。

    public static class SqlPlus
    {

        // Hashtable to store cached parameters
        private static Hashtable parmCache = Hashtable.Synchronized(new Hashtable());

        public static string connectionString = "Data Source=spsserver;Initial Catalog=Cooec;uid=sa;pwd=ssssaaaa";

        public static SqlTransaction GetTransaction()
        {
            using (SqlConnection connection = new SqlConnection(SqlPlus.connectionString))
            {
                connection.Open();
                SqlTransaction trans = connection.BeginTransaction();
                return trans;
            }
        }

        public static void ConnClose(SqlConnection connection)
        {
            if (connection.State == ConnectionState.Open)
            {
                connection.Close();
            }
        }

        public static int ExecuteNonQuery(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            using (SqlConnection conn = new SqlConnection(SqlPlus.connectionString))
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                int val = cmd.ExecuteNonQuery();
                cmd.Parameters.Clear();
                return val;
            }
        }

        public static int ExecuteNonQuery(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {

            SqlCommand cmd = new SqlCommand();

            PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
            int val = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            return val;
        }

        public static int ExecuteNonQuery(SqlTransaction trans, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            PrepareCommand(cmd, trans.Connection, trans, cmdType, cmdText, commandParameters);
            int val = cmd.ExecuteNonQuery();
            cmd.Parameters.Clear();
            return val;
        }

        public static SqlDataReader ExecuteReader(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            SqlConnection conn = new SqlConnection(SqlPlus.connectionString);

            // we use a try/catch here because if the method throws an exception we want to 
            // close the connection throw code, because no datareader will exist, hence the 
            // commandBehaviour.CloseConnection will not work
            try
            {
                PrepareCommand(cmd, conn, null, cmdType, cmdText, commandParameters);
                SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
                cmd.Parameters.Clear();
                return rdr;
            }
            catch
            {
                conn.Close();
                throw;
            }
        }

        public static object ExecuteScalar(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();

            using (SqlConnection connection = new SqlConnection(SqlPlus.connectionString))
            {
                PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
                object val = cmd.ExecuteScalar();
                cmd.Parameters.Clear();
                return val;
            }
        }

        public static object ExecuteScalar(SqlConnection connection, CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {

            SqlCommand cmd = new SqlCommand();

            PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
            object val = cmd.ExecuteScalar();
            cmd.Parameters.Clear();
            return val;
        }

        public static DataTable ExecuteDataTable(CommandType cmdType, string cmdText, params SqlParameter[] commandParameters)
        {
            SqlCommand cmd = new SqlCommand();
            DataTable oTab = new DataTable();
            using (SqlConnection connection = new SqlConnection(SqlPlus.connectionString))
            {
                PrepareCommand(cmd, connection, null, cmdType, cmdText, commandParameters);
                SqlDataAdapter adp = new SqlDataAdapter(cmd);
                adp.Fill(oTab);
            }
            return oTab;
        }

        public static void CacheParameters(string cacheKey, params SqlParameter[] commandParameters)
        {
            parmCache[cacheKey] = commandParameters;
        }

        public static SqlParameter[] GetCachedParameters(string cacheKey)
        {
            SqlParameter[] cachedParms = (SqlParameter[])parmCache[cacheKey];

            if (cachedParms == null)
                return null;

            SqlParameter[] clonedParms = new SqlParameter[cachedParms.Length];

            for (int i = 0, j = cachedParms.Length; i < j; i++)
                clonedParms[i] = (SqlParameter)((ICloneable)cachedParms[i]).Clone();

            return clonedParms;
        }

        private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, CommandType cmdType, string cmdText, SqlParameter[] cmdParms)
        {

            if (conn.State != ConnectionState.Open)
                conn.Open();

            cmd.Connection = conn;
            cmd.CommandText = cmdText;

            if (trans != null)
                cmd.Transaction = trans;

            cmd.CommandType = cmdType;

            if (cmdParms != null)
            {
                foreach (SqlParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        }
    }

    public static class Database
    {
        public static SqlParameter MakeInParam(string parameterName, SqlDbType dbType, int size)
        {
            SqlParameter sqlPar = new SqlParameter(parameterName, dbType, size);
            return sqlPar;
        }
        public static SqlParameter MakeInParam(string parameterName, SqlDbType dbType, int size, object oValue)
        {
            SqlParameter sqlPar = new SqlParameter(parameterName, dbType, size);
            sqlPar.Value = oValue;
            return sqlPar;
        }
        public static SqlParameter MakeInParam(string parameterName, SqlDbType dbType, int size, string sValue)
        {
            SqlParameter sqlPar = new SqlParameter(parameterName, dbType, size);
            sqlPar.Value = sValue;
            return sqlPar;
        }
        public static SqlParameter MakeInParam(string parameterName, SqlDbType dbType, int size, int iValue)
        {
            SqlParameter sqlPar = new SqlParameter(parameterName, dbType, size);
            sqlPar.Value = iValue;
            return sqlPar;
        }
        public static SqlParameter MakeInParam(string parameterName, SqlDbType dbType, int size, DateTime dValue)
        {
            SqlParameter sqlPar = new SqlParameter(parameterName, dbType, size);
            if (dValue == DateTime.MinValue)
                sqlPar.Value = DBNull.Value;
            else
                sqlPar.Value = dValue;
            return sqlPar;
        }
        public static SqlParameter MakeInParam(string parameterName, SqlDbType dbType, int size, double dValue)
        {
            SqlParameter sqlPar = new SqlParameter(parameterName, dbType, size);
            sqlPar.Value = dValue;
            return sqlPar;
        }
        public static string ValueToString(object oValue)
        {
            if (oValue == System.DBNull.Value)
                return "";
            else
                return oValue.ToString();
        }
        public static DateTime ValueToDateTime(object oValue)
        {
            if (oValue == System.DBNull.Value)
                return DateTime.MinValue;
            else
                return Convert.ToDateTime(oValue);
        }
        public static int ValueToInt(object oValue)
        {
            if (oValue == System.DBNull.Value)
                return int.MinValue;
            else
                return Convert.ToInt32(oValue);
        }
    }