Entity Framework学习三：查询、插入、更新和删除操作

1.LINQ过滤数据 

var query = from person in context.People
                        where person.FirstName.StartsWith("a")
                        select person;
var methodQuery = context.People.Where(p => p.FirstName.StartsWith("a"));

两种不同的写法，效果一样。

• 多条件组合查找

var query = from person in context.People
                        where person.FirstName.StartsWith("a") &&
                        person.LastName.EndsWith("b")
                        select person;
var methodQuery = context.People.Where(p => p.FirstName.StartsWith("a") && p.LastName.EndsWith("b"));

• 对查找结果排序

            var query = from person in context.People
                        where person.FirstName.StartsWith("a") &&
                        person.LastName.EndsWith("b")
                        orderby person.FirstName,person.LastName
                        select person;
            var methodQuery = context.People
                .Where(p => p.FirstName.StartsWith("a") && p.LastName.EndsWith("b"))
                .OrderBy(p => p.FirstName)
                .ThenBy(p => p.LastName);