Home  >  Article  >  Backend Development  >  For example, we want to query the names and ages of users in Shanghai who have made at least 3 purchases worth 10 bucks in the past 10 months from the user table customer and user order table orders. If it is written in the traditional way, I don’t know how much code needs to be written, and various complex processing logic makes the semantics of the code very unclear. However, if it is written in LINQ, it will be as follows:

For example, we want to query the names and ages of users in Shanghai who have made at least 3 purchases worth 10 bucks in the past 10 months from the user table customer and user order table orders. If it is written in the traditional way, I don’t know how much code needs to be written, and various complex processing logic makes the semantics of the code very unclear. However, if it is written in LINQ, it will be as follows:

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PHP中文网Original
2017-06-17 16:23:211472browse
var results = from customer in customers
              where customer.State == "WA"
              let custOrders = (from order in orders
                                where customer.ID == order.ID
                                select new { order.Date, order.Amount })
              where custOrders.Count(co => co.Amount >= 10 &&
                                     co.Date >= DateTime.Now.AddMonths(−10)) >= 3
              select new { customer.Name, customer.Age };<br><br>下面另附上一条分页的linq语句:<br>var productList=(from prod in db.Products<br>where prod.Type="零食" orderby prod.datatime select u).Skip(PageSize*(PageNum-1)).Take(PageSize);

The above is the detailed content of For example, we want to query the names and ages of users in Shanghai who have made at least 3 purchases worth 10 bucks in the past 10 months from the user table customer and user order table orders. If it is written in the traditional way, I don’t know how much code needs to be written, and various complex processing logic makes the semantics of the code very unclear. However, if it is written in LINQ, it will be as follows:. For more information, please follow other related articles on the PHP Chinese website!

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