C# LINQ or for loop How to get a data source from a db?

Question

I am trying to get the count of each item in the column that are the same value. for example i have a table that has people info and i want it to go through the first name column and get me a count of how many Joe's and Mary's are in there without specifying a certain name.

Does this answer your question? [how to use group by in a linq query?](https://stackoverflow.com/questions/11069876/how-to-use-group-by-in-a-linq-query) — XAMT, Mar 16 '20 at 17:46

Alex - Tin Le · Accepted Answer · 2020-03-16T21:28:35.067

1

You can group your data by column

users.GroupBy(x => x.FirstName).Select(x => new
{
    FirstName = x.Key,
    Count = x.Count()
});

edited Mar 16 '20 at 21:28

answered Mar 16 '20 at 17:55

Alex - Tin Le

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score 1 · Answer 2 · answered Mar 16 '20 at 18:05

Try use GroupBy:

public class People
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }

    static void Main(string[] args)
    {
        var peoples = new List<People>
        {
            new People { Id = 1, FirstName = "Bob", LastName = "Abc" },
            new People { Id = 2, FirstName = "Joe's", LastName = "Def" },
            new People { Id = 3, FirstName = "Mary's", LastName = "Ghi" },
            new People { Id = 4, FirstName = "Alice", LastName = "Jikl" },
            new People { Id = 5, FirstName = "Bob", LastName = "Mno" },
        };

        var groupedByFirstName = peoples
            .GroupBy(x => x.FirstName)
            .Select(x => new
            {
                FirstName = x.Key,
                Count = x.Count()
            });

        foreach (var people in groupedByFirstName)
        {
            Console.WriteLine($"FirstName: {people.FirstName}. Count: {people.Count}");
        }

        Console.ReadKey();
    }
}

C# LINQ or for loop How to get a data source from a db?

2 Answers2