C# and Linq: Where clause contains some value and exludes other values

Question

Using the .net Framework 4.8 I'm trying to write an some Linq where the Where clause contains items meeting certain criteria - but excludes a subset of those items meeting some other conditions. Here's a summary of the situation and I will provide full sample code below:

I have a list of objects where 2 properties are:
ParmDir (string: i.e. IN, OUT, INOUT)
ParmName (string: i.e. @Id, @Parm1, @ErrorLogId, @OutParm1, @OutParm2, etc....)

1) I want to filter the list where ParmDir contians "IN" or "INOUT".
2) Of those, I want to exclude any items where the ParmName contains "@ErrorLogId".

I have step one working:

var including = new string[] { "OUT", "INOUT" };  
outPutCount = list.Where(x => including.Contains(x.ParmDir)).Count();  

But what is the syntax to exclude something like:

var excluding = new string[] { "ErrorLogId" };  
x <> excluding.Contains(x.ParmName)  

//So the full statement would be something like this:

var including = new string[] { "OUT", "INOUT" };  
var excluding = new string[] { "ErrorLogId" };  
outPutCount = list.Where(x => including.Contains(x.ParmDir) && x <> excluding.Contains(x.ParmName)).Count();  

Thanks.

Here's all the code to test in a console app:

class Program  
{  
    static void Main(string[] args)  
    {  
        List<Parm> list = new List<Parm>();  
        list.Add(new Parm("@Id", "IN", 1, "uniqueidentifier"));  
        list.Add(new Parm("@Parm1", "IN", 2, "varchar"));  
        list.Add(new Parm("@Parm2", "IN", 3, "int"));  
        list.Add(new Parm("@Parm3", "IN", 4, "decimal"));  
        list.Add(new Parm("@ErrorLogId", "INOUT", 4, "uniqueidentifier"));  
        list.Add(new Parm("@OutParm1", "OUT", 5, "int"));  
        list.Add(new Parm("@OutParm2", "INOUT", 6, "varchar"));  
        list.Add(new Parm("@OutParm3", "INOUT", 7, "decimal"));  
        list.Add(new Parm("@OutParm4", "INOUT", 8, "int"));  

        int totalCount = 0;  
        int outPutCount = 0;  
        int errorLogCount = 0;  

        totalCount = (from x in list select x).Count();  

        var including = new string[] { "OUT", "INOUT" };  
        var excluding = new string[] { "ErrorLogId" };  
        outPutCount = list.Where(x => including.Contains(x.ParmDir)).Count();  

        Console.WriteLine("totalCount = " + totalCount.ToString());  
        Console.WriteLine("outPutCount = " + outPutCount.ToString());  
    }  

    public class Parm  
    {  
        string _parmName;  
        string _parmDir;  
        int _sort;  
        string _sQLDataType;  

        public Parm(string parmName, string parmDir, int sort, string sQLDataType)  
        {  
            _parmName = parmName;  
            _parmDir = parmDir;  
            _sort = sort;  
            _sQLDataType = sQLDataType;  
        }  
        public string ParmName { get => _parmName; set => _parmName = value; }  
        public string ParmDir { get => _parmDir; set => _parmDir = value; }  
        public int Sort { get => _sort; set => _sort = value; }  
        public string SQLDataType { get => _sQLDataType; set => _sQLDataType = value; }  
    }  
}  

Answer 1

Try to use != to determine whether the strings are equal:

            var re = list.Where(x => including.Contains(x.ParmDir) && x.ParmName != "@ErrorLogId");  

Or

        var excluding = new string[] { "@ErrorLogId" };  
        var re = list.Where(x => including.Contains(x.ParmDir) && !excluding.Contains(x.ParmName));  

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