C# 判断某列是否为主键

/// <summary>
    /// 判断某列是否为主键
    /// </summary>
    /// <param name="columnName">列的物理名称</param>
    /// <param name="tableName">表名</param>
    /// <returns></returns>
    public bool IsPrimaryKey(String columnName,String tableName)
    {
        SqlParameter[] parameters = new SqlParameter[3];
        parameters[0] = new SqlParameter("@table_name", tableName);
        parameters[1] = new SqlParameter("@table_owner", null);
        parameters[2] = new SqlParameter("@table_qualifier", null);
        DataRowCollection drc = SqlHelper.ExecuteDataset(Common.GetConnString, CommandType.StoredProcedure, "sp_pkeys", parameters).Tables[0].Rows;
        if (drc.Count==0 || (drc[0]["COLUMN_NAME"].ToString() != columnName))
            return false;
        else
            return true;


    }