有关C# SQL 查询语句!多表查询，具体如下所示：

Question

我现在要根据tFavorites这个表里的ItemSysNo(也就是文章编号)，来获取tTechnoThesis这个表里的 Title(文章名)和ReadCount(查看次数)然后还要获取tFavorites这个表里的FavouritesTime(添加时间)！格式是string sql = "select a.SysNo,a.Title,a.CreateUserSysNo,a.Content,a.CreateTime,a.RankSysNo,a.TypeSysNo,a.Status,a.ReferenceClassSysNo,a.ReferenceSysNo,b.LevelIndex CustomerRank,"+ " case when a.IsCustomer = " + ((int)AppEnum.YNStatus.Yes).ToString() + " then b.CustomerId else '管理员' end as CustomerId"+ " from tCommentMaster a left join tCustomer b on a.CreateUserSysNo = b.SysNo where a.IsCustomer = " + ((int)AppEnum.YNStatus.Yes).ToString()+ " and b.SysNo = " + UserSysNo.ToString();这样的格式写``麻烦高人给个代码``感谢万分！！！tFavorites表里有SysNo ItemSysNo CustomerSysNo FavouritesTime这4列我要代码啊`我就是不会写`才问的`麻烦`谁可以帮我写一个啊！感谢！

Answer 1

case a.IsCustomer
when ((int)AppEnum.YNStatus.Yes).ToString()
then b.CustomerId
else '管理员'

Answer 2

写个过程吧
传参进去