How to query for exact value within a delimited field inside a DataTable-CodePudding

SO I have a DataTable with a few fields populated from Rest (not all listed), I have a treeview populated with delineated tree from path in the DT. I want to be able to select any portion of the tree and generate an array of the all the matches. Problem I'm running into is that if I search for M19, I get everything that contains M19... including M198. I can make this work with parsing out the Path and doing an exact... but it's really ugly and very slow and add an entire new loop. Is there a more elegant way to code this?

Sample Code:
        public string[] GetNodeID(string locName)
        {
            
            var results = from myRow in locationData.AsEnumerable()
                          where myRow.Field<string>("Path").ToUpper().Contains(locName.ToUpper())
                          select myRow;
            DataView view = results.AsDataView();



            return null;
        }

Example Tree
Main
->M19
-> ->M19-I1
-> ->M19-I2
-> M198
-> -> M198-I1
-> -> M198-I2

locationData Table
ID Path                 Description
0  Main\M19             Null
1  Main\M19\M19-I1      Instrument 1
2  Main\M19\M19-I2      Instrument 2
3  Main\M198\M198-I1    Instrument 1
4  Main\M198\M198-I2    Instrument 2

CodePudding user response：

You can split the Path field by the \ and - separators to create a string array and search the substrings for a given branch or node:

//  
// using System.Linq;

public string[] GetTreeBranch(DataTable dt, string branch) => dt.AsEnumerable()
    .Where(x => x.Field<string>("Path").Split('\\', '-')
    .Any(y => y.Equals(branch, StringComparison.OrdinalIgnoreCase)))
    .Select(x => x.Field<string>("Path")).ToArray();

Alternatively, use RegEx to search the Path field for a match. Append \b to the given branch to create a whole-word-search pattern (i.e. m19\b) to skip the other branches like M198. Online Test.

//  
// using System.Text.RegularExpressions;

public string[] GetTreeBranch(DataTable dt, string branch) => dt.AsEnumerable()
    .Where(x => Regex.IsMatch(
        x.Field<string>("Path"), $@"{branch}\b", RegexOptions.IgnoreCase))
    .Select(x => x.Field<string>("Path")).ToArray();

Either way, calling:

var s = "m19";

Console.WriteLine(string.Join(", ", GetTreeBranch(locationData, s)));

Yields:

Main\M19, Main\M19\M19-I1, Main\M19\M19-I2