Error when splitting and replacing chars C# email with LINQ Array Index not supported in LINQ

问题

This throws an error 'ArrayIndex' is not supported in LINQ to Entities. so what would be an alternative for this as the split and replace fails?

from S in db.Students
where S.ID = ID
select new { S.EMAIL.Split('@')[0].Replace(".", " ,"), S.NAME };

This is for a list of Students and this is how I currently can add them.

mylist.DataValueField = "email";
mylist.DataTextField = "name";

This fails:

S.EMAIL.Split('@')[0].Replace(".", " ,")

Please help.

Thanks

回答1:

If you want it to run on the SQL server you can use IndexOf and Substring:

from S in db.Students
where S.ID = ID
select new 
{ 
    EMAIL = (S.EMAIL.Contains("@") ? 
                S.EMAIL.Substring(0, S.EMAIL.IndexOf("@")) : 
                S.EMAIL
            ).Replace(".", " ,")
  , S.NAME 
};

回答2:

You could do the following

var query =  (from S in db.Students
             where S.ID = ID
             select new { 
                 S.EMAIL, 
                 S.NAME })
             .AsEnumerable()
             .Select(x => new {
                  EMAIL = x.EMAIL.Split('@')[0].Replace(".", " ,"), 
                  NAME = x.NAME});

So that the splitting and replacing is done in linq to objects instead of the DB.

来源：https://stackoverflow.com/questions/29540398/error-when-splitting-and-replacing-chars-c-sharp-email-with-linq-array-index-not