PrepareCommand执行参数查询

/// <summary>
/// 执行参数查询
/// </summary>
/// <param name="cmd">数据库执行命令</param>
/// <param name="conn">数据库链接命令</param>
/// <param name="trans">事务</param>
/// <param name="cmdText">查询语句</param>
/// <param name="cmdParms">查询参数</param>
/// <returns></returns>
private static void PrepareCommand(SqlCommand cmd, SqlConnection conn, SqlTransaction trans, 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 = CommandType.Text;//cmdType;
            if (cmdParms != null)
            {
                foreach (SqlParameter parameter in cmdParms)
                {
                    if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) &&
                        (parameter.Value == null))
                    {
                        parameter.Value = DBNull.Value;
                    }
                    cmd.Parameters.Add(parameter);
                }
            }
        }