What .NET StringComparer is equivalent SQL's Latin1_General_CI_AS

Question

I am implementing a caching layer between my database and my C# code. The idea is to cache the results of certain DB queries based on the parameters to the query. The database i

Answer 1

The following is much simpler:

System.Globalization.CultureInfo.GetCultureInfo(1033)
              .CompareInfo.GetStringComparer(CompareOptions.IgnoreCase | CompareOptions.IgnoreKanaType | CompareOptions.IgnoreWidth)

It comes from https://docs.microsoft.com/en-us/dotnet/api/system.globalization.globalizationextensions?view=netframework-4.8

It computes the hashcode correctly given the options given. You'll still have to trim trailing spaces manually, as they as discarded by ANSI sql but not in .net

Here is a wrapper that trims spaces.

using System.Collections.Generic;
using System.Globalization;

namespace Wish.Core
{
    public class SqlStringComparer : IEqualityComparer
    {
        public static IEqualityComparer Instance { get; }

        private static IEqualityComparer _internalComparer =
            CultureInfo.GetCultureInfo(1033)
                       .CompareInfo
                       .GetStringComparer(CompareOptions.IgnoreCase | CompareOptions.IgnoreKanaType | CompareOptions.IgnoreWidth);



        private SqlStringComparer()
        {
        }

        public bool Equals(string x, string y)
        {
            //ANSI sql doesn't consider trailing spaces but .Net does
            return _internalComparer.Equals(x?.TrimEnd(), y?.TrimEnd());
        }

        public int GetHashCode(string obj)
        {
            return _internalComparer.GetHashCode(obj?.TrimEnd());
        }

        static SqlStringComparer()
        {
            Instance = new SqlStringComparer();
        }
    }
}