query = (from c in query
                         where c.CompanyName.Contains(fotbordoc["CompanyName"].value.ToString())
                         select c).AsQueryable<Customer>();

select ... from Customer where CompanyName like @p1

var query = db.GetCutmors().AsEnumerable();

            foreach (var cond in conditions)
            {
                query = query.Where(filterExpressions[cond.field](cond.value));

            }

select ... from Customer 

 var query = db.GetCutmors().AsQueryable();

            foreach (var cond in conditions)
            {
                query = query.Where(filterExpressions[cond.field](cond.value)).AsQueryable();

            }
            bindingSource1.DataSource = query;

    var query = db.Customers.AsQueryable();
      query = query.Where(c => c.CompanyName.Contains("ch"));

exec sp_executesql N'SELECT [t0].[CustomerID], [t0].[CompanyName], [t0].[ContactName], [t0].[ContactTitle], [t0].[Address], [t0].[City], 
[t0].[Region], [t0].[PostalCode], [t0].[Country], [t0].[Phone], [t0].[Fax]
FROM [dbo].[Customers] AS [t0]
WHERE [t0].[CompanyName] LIKE @p0',N'@p0 nvarchar(4)',@p0=N'%ch%'

            var query = db.Customers.AsQueryable();
            Func<Customer, bool> searchFilter = delegate(Customer c) { return c.CompanyName.Contains("ch"); };
            query = query.Where(searchFilter).AsQueryable();

 
Func<Customer, bool> searchFilter = delegate(Customer c) { return c.CompanyName.Contains("ch"); };

Expression<Func<Customer, bool>> serverfilter = c => c.CompanyName.Contains("ch");   

Dictionary<string, Func<object, Expression<Func<Customer, bool>>>> filterExpressions =
    new Dictionary<string, Func<object, Expression<Func<Customer, bool>>>>() 
{
	{"CompanyName", (p) => ((customer) => customer.CompanyName.Contains( p.ToString()))},
	{"ContactName", (p) => ((customer) => customer.ContactName.Contains(p.ToString()))},
	{"Country", (p) => ((customer) => customer.Country.Contains( p.ToString()))}
};

 public class filt_field
        {
            public string field { get; set; }
            public string value { get; set; }
        }
public List<filt_field> conditions = new List<filt_field>();

 conditions.Clear();
if (textBox1.Text.Trim() != String.Empty)
                conditions.Add(new filt_field { field = "CompanyName", value = textBox1.Text });

 void ReadDoc()
        {
            var query = db.Customers.AsQueryable();            
            foreach (var cond in conditions)
            {
                query = query.Where(filterExpressions[cond.field](cond.value)).AsQueryable();

            }
            bindingSource1.DataSource = query;

        }

Dictionary<string, Func<object, Expression<Func<Customer, bool>>>> filterExpressions =
    new Dictionary<string, Func<object, Expression<Func<Customer, bool>>>>() 
{
	{"CompanyName", (p) => ({(customer) => 
if (p.TypeOtborLike) // отбор типа like
customer.CompanyName.Contains( p.ToString()))
else if ((p.TypeEqul) // отбор типа точное совпадениеп
customer.CompanyName== p.ToString())
// и так далее
}},