请问一个困扰很久的and or动态多条件组合查询的有关问题

请教一个困扰很久的and or动态多条件组合查询的问题

C# code

    /// <summary>    /// 产品价格范围条件    /// </summary>    public class PriceCondition    {        public string Name { get; set; }        public float Min { get; set; }        public float Max { get; set; }    }    public class Demo    {        public static void Main()        {            List<PriceCondition> conditions = new List<PriceCondition>();    //价格范围条件            //添加条件            conditions.Add(                new PriceCondition()                {                    Name = "100元以下",                    Min = 0,                    Max = 100                });            conditions.Add(                new PriceCondition()                {                    Name = "151～180元",                    Min = 150,                    Max = 180                });            conditions.Add(                new PriceCondition()                {                    Name = "300元以上",                    Min = 300,                    Max = 0                });            Search(conditions, "关键字");        }        //最终想实现类似T-SQL效果: select * from Product where Name like '%关键字%' and ((price<=100) || (price>150 and price<=180) || (price>300))        public List<Product> Search(List<PriceCondition> priceRange, string keywords)        {            var query = from p in Product.Table select p;            if (!string.IsNullOrEmpty(keywords))            {                query = from p in query where p.Name.Contains(keywords) select p;            }            if (priceRange.Count > 0)            {                foreach (var price in priceRange)                {                    //这里该怎么写？                }            }            return query.ToList();        }    }

C# code

using System;using System.Collections.Generic;namespace Test{    /// <summary>    /// 产品价格范围条件    /// </summary>    public class PriceCondition    {        public string Name { get; set; }        public float Min { get; set; }        public float Max { get; set; }    }    public class Demo    {        public static void Main()        {            List<PriceCondition> conditions = new List<PriceCondition>();    //价格范围条件            //添加条件            conditions.Add(                new PriceCondition()                {                    Name = "100元以下",                    Min = 0,                    Max = 100                });            conditions.Add(                new PriceCondition()                {                    Name = "101～200元",                    Min = 101,                    Max = 200                });            conditions.Add(                new PriceCondition()                {                    Name = "200元以上",                    Min = 200,                    Max = 0                });            Predicate<PriceCondition> macth = p => p.Name.Contains("1") && p.Max <= 33333;            List<PriceCondition> list = Search(conditions, macth);            foreach (PriceCondition price in list)            {                Console.WriteLine(price.Name);            }            Console.ReadKey();        }        //最终想实现类似T-SQL效果: select * from Product where Name like '%关键字%' and ((price<=100) || (price>100 and price<=200) || (price>200))        public static List<PriceCondition> Search(List<PriceCondition> priceRange, Predicate<PriceCondition> macth)        {            return priceRange.FindAll(macth);        }    }}
[解决办法]
C# code 
 
void Main(){     List<PriceCondition> conditions = new List<PriceCondition>();    //价格范围条件            //添加条件            conditions.Add(                new PriceCondition()                {                    Name = "100元以下",                    Min = 0,                    Max = 100                });            conditions.Add(                new PriceCondition()                {                    Name = "151～180元",                    Min = 150,                    Max = 180                });            conditions.Add(                new PriceCondition()                {                    Name = "300元以上",                    Min = 300,                    Max = 0                });                    Search(conditions, "关键字");}        public List<Product> Search(List<PriceCondition> priceRange, string keywords)        {            Expression<Func<Product, bool>> expression = PredicateExtensions.True<Product>();                         if (!string.IsNullOrEmpty(keywords))            {                expression=expression.And(p=>p.Name.Contains(keywords));            }                             foreach (var price in priceRange)            {                 expression=expression.Or(p=>(price.Min>0 && p.Price >price.Min) && (price.Max>0 && p.Price <price.Max));             }                        return Product.Table.Where(expression).ToList();        }    /// <summary>    /// 产品价格范围条件    /// </summary>    public class PriceCondition    {        public string Name { get; set; }        public float Min { get; set; }        public float Max { get; set; }    }              // Product         public class Product        {          public string Name{get;set;}          public float Price{get;set;}        }                public static class PredicateExtensions{    public static Expression<Func<T, bool>> True<T>() { return f => true; }     public static Expression<Func<T, bool>> False<T>() { return f => false; }     public static Expression<Func<T, bool>> Or<T>(this Expression<Func<T, bool>> expression1,            Expression<Func<T, bool>> expression2)    {        var invokedExpression = Expression.Invoke(expression2, expression1.Parameters.Cast<Expression>());         return Expression.Lambda<Func<T, bool>>(Expression.Or(expression1.Body, invokedExpression),            expression1.Parameters);    }     public static Expression<Func<T, bool>> And<T>(this Expression<Func<T, bool>> expression1,             Expression<Func<T, bool>> expression2)    {        var invokedExpression = Expression.Invoke(expression2, expression1.Parameters.Cast<Expression>());         return Expression.Lambda<Func<T, bool>>(Expression.And(expression1.Body,           invokedExpression), expression1.Parameters);    }}