How to make a query through LINQ ignoring accents?

You only get this if you set the COLLATION of the column (or the table, or the bank) before. There are a few ways to do this.

One of these is defining a base initializer , like this:

public class CollationInitializer : CreateDatabaseIfNotExists<MeuContexto>
{
    public override void InitializeDatabase(MeuContextocontext)
    {
        if(!context.Database.Exists())
        {
            using (SqlConnection connection = new SqlConnection("DefaultConnection"))
            {
                connection.Open();
                using(SqlCommand command = new SqlCommand(string.Format("CREATE DATABASE {0} COLLATE Latin1_General_CI_AI", "MinhaBaseDeDados"), connection))
                {
                    command.ExecuteNonQuery();
                }
            }

            SqlConnection.ClearAllPools();
         }

         base.InitializeDatabase(context);
    }
}

E:

public class MeuContexto: DbContext
{
    public MeuContexto() : base("DefaultConnection", throwIfV1Schema: false)
    {
        Database.SetInitializer(new CollationInitializer<MeuContexto>());
        if(!Database.Exists())
        {
            Database.Initialize(true);
         }
     } 
}

Another is setting up a migration interceptor to set COLLATION to the time the database is being updated:

public class CreateDatabaseCollationInterceptor : IDbCommandInterceptor
{
    private readonly string _collation;

    public CreateDatabaseCollationInterceptor(string collation)
    {
        _collation = collation;
    }

    public void NonQueryExecuted(DbCommand command, DbCommandInterceptionContext<int> interceptionContext) { }
    public void NonQueryExecuting(DbCommand command, DbCommandInterceptionContext<int> interceptionContext)
    {
        // Apenas para SQL Server
        if (Regex.IsMatch(command.CommandText, @"^create database \[.*]$"))
        {
            command.CommandText += " COLLATE " + _collation;
        }
    }

    public void ReaderExecuted(DbCommand command, DbCommandInterceptionContext<DbDataReader> interceptionContext) { }
    public void ReaderExecuting(DbCommand command, DbCommandInterceptionContext<DbDataReader> interceptionContext) { }
    public void ScalarExecuted(DbCommand command, DbCommandInterceptionContext<object> interceptionContext) { }
    public void ScalarExecuting(DbCommand command, DbCommandInterceptionContext<object> interceptionContext) { }
}

In SQL Server it is possible to change the collation of a column " on the fly" during a Select .

Something like:

Select *
From Entidades
Where (Coluna Collate SQL_Latin1_General_CP1_CI_AI) Like 'Tê%'

This query returns all rows where the Nome column starts with "Te" regardless of whether or not casing accents or differences in>. For example: " Test ", " Test ", " Test ". Note also that the parameter uses an accent, I did this to illustrate that it is also inconsiderate.

Obviously you will need to write the query to execute it, but I think this is not a problem.

I made an example running this query with Entity Framework.

const string collation = "SQL_Latin1_General_CP1_CI_AI";

using (var db = new Contexto())
{
    var resultado = db.Database.SqlQuery<Entidade>($"Select * From Entidades
                                                     Where (Nome Collate {collation}) 
                                                     Like '%{param}%'").ToList();
}

A simple way I found was like this. I use entity framework with mysql and utf8 -default collation,

using (controle_estoqueEntities entity = new controle_estoqueEntities())
        {
            return (from a in entity.clientes
                    where ( (a.nome_cliente == nome || a.nome_cliente.Contains(nome)))  
                    orderby a.nome_cliente
                    select new ClienteDTO
                    {IdCliente = a.idcliente,
                        NomeCliente = a.nome_cliente}).toList();

}