What is the method of using c# linq?

In C#, LINQ (Language Integrated Query) is a unified programming pattern used for querying data. It offers a SQL-like syntax to query, filter, sort, and transform various data sources such as collections, arrays, database tables, etc. Here are some commonly used methods of LINQ:

1. Specify the data source using the “from” keyword.
2. Specify the query condition using the “where” keyword.
3. Use the select keyword to specify the data to be selected.

var query = from item in collection
            where item.Property == value
            select item;

1. Specify the filter conditions using the ‘where’ keyword.

var query = collection.Where(item => item.Property == value);

1. Specify the sorting criteria using the orderby keyword.
2. You can use the keywords “ascending” or “descending” to specify the sort order as ascending or descending.

var query = from item in collection
            orderby item.Property ascending
            select item;

1. You can use the select keyword to transform data.
2. You can create a new anonymous type using the select new keyword.

var query = from item in collection
            select new { Name = item.Name, Age = item.Age };

1. Calculate the quantity using the Count() method.
2. Calculate the total using the Sum() method.
3. Calculate the average using the Average() method.
4. Use the Max() method to find the maximum value.
5. Find the smallest value using the Min() method.

var count = collection.Count();
var sum = collection.Sum(item => item.Property);
var average = collection.Average(item => item.Property);
var max = collection.Max(item => item.Property);
var min = collection.Min(item => item.Property);

These are just some common uses of LINQ, there are more operations (such as grouping, joining, subquery, etc.) that can be learned and used based on specific needs.